Lim Wei Liang:
What is the real value of tropical forests? By now, you may have heard a lot about the two most important and commonly recognized services that tropical rain forests provide to the humanity:
Amazon Tropical Forest Brazil
Amazon Tropical Forest Brazil
Amazon Tropical Forest, Brazil
They regulate global climate patterns and help mitigate negative effects of climate change, specifically, global climate warming, (Service 1), and
They serve as storages of global biodiversity, specifically plant and animal diversity (Service 2).
Those are the two main factors that have been widely put forward as the arguments which are strong enough for us people to try to do our utmost to “save the rain forests” from their continuous destruction.
Rain Forest Service 1 – Regulating Climate Patterns
There is a strong interdependent relationship between the climate and the tropical rain forests. On the one hand , favourable local climatic conditions determine the existence of rain forests in principle in a certain location. (2)
For example, true tropical rain forests can only exist in geographical locations with “continuous supply” of rainfall and sunshine. Such locations are mostly found in the geographical areas around the equator. On the other hand , rain forests affect the global climatic conditions by acting as pollution filters / “carbon sinks” / “lungs of the earth”.
Rain forest trees absorb carbon dioxide (CO2) and produce oxygen back into the atmosphere, by way of photosynthesis. (3)
In very simple terms, such carbon absorption by rain forests helps reduce the amount of CO2 that could otherwise be released into the Earth’s atmosphere and cause global warming . (4)
Rain Forest Service 2 – Biodiversity
Biodiversity (biological diversity) is defined as a number and variety of plant and animal species in a certain habitat.
We know that tropical rain forests have the highest levels of biodiversity, as compared to any other place in the world.
For example, from one of the UN Chronicle issues we learn that a 2,500-acre area of a typical tropical rain forest is home to some 1,500 species of flowering plants, 750 species of trees, 400 species of birds and 150 different species of butterflies. (5)
In another example, check out some facts about the Ecuador rainforest , one of the most biodiverse places on the planet.
Endangered Orangutans
Endangered Orangutans
Endangered Orangutans
Rain forests are home to a large number of endangered animals , such as the mountain gorilla , which are crucial components of tropical biodiversity.
But why is it so important for us to preserve biodiversity as much as we only can?
From the utilitarian point of view, the common answer to that question is:
If we continue to lose biodiversity, we are going to lose out on potential discoveries of new foodstuffs, medicines, industrial raw materials.
This is not to mention the fact that it would be nice for the human race to allow other life forms, that comprise biodiversity as such, to live peacefully, just because they already exist.
More on Rainforest Services
It goes without saying that the two services we’ve described above are of crucial importance.
But let’s take a closer look at the uses of tropical rain forests.
A. Rain Forests As Habitats
For thousands of years, rain forests had been home for all the life forms residing in them, including animals and humans (forest (indigenous) people).
Rainforest Toucan
Rainforest Toucan
Toucans call rainforest home
Animals had been utilizing their natural habitats as their needs guided them (by “taking” whatever they needed from their environment (such as food) and “giving back” in some other way (for example, by becoming “food” for some larger predators).
Forest people, on their part, had been historically using rain forest resources in very sustainable ways (6) – the knowledge they had been gathering over centuries from their ancestors and transferring to their offspring.
In most recent times (the last several decades) rain forests have also become home to many new peasant settlers / migrants who moved to their new habitats as a result of their governments’ resettlement programmes, in search of new land for agricultural purposes. (7)
B. Rain Forests As Resource Bases
Following on from the discussion of biodiversity above, it is no surprise that the tropical rain forests are sometimes referred to as an "inexhaustible treasure trove" of nature . (8)
We can distinguish three major groups of goods that come from the rain forests:
food
medicines / drugs
commercial / industrial goods
Since the middle ages, tropical rain forests attracted the attention of many European travellers.
The large-scale exploitation of rain forest resources must have started as one of by-products of the industrial revolution in Europe in the 18 th – 19 th centuries. Rubber was one of the rain forest’s most prominent products, which indeed found many uses in newly born industrial societies. And perhaps, one of its most famous applications was for rubber tyres which were originally used in bicycles, and consequently in motor cars. (9)
As for the foodstuffs, you wouldn’t believe how much food that we consume every day originated from the rain forests.
Coffee Bean Harvester
Coffee Bean Harvester
Coffee Bean Harvester Vanilla and cacao beans (used to make chocolate), for example, were discovered during the very early voyages of the conquistadors to the Americas. (10)
It is hard to overestimate the importance of rain forest food products in modern times.
Chris Park mentions that about 12 crops provide 90% of the world’s food and half of them come from tropical rain forests including rice and maize . (11)
Even the domestic chicken was apparently bred from the red jungle fowl of Indian forests. (12)
Products like coffee , bananas , tea , sugar , pineapples , avocados and a lot more are widely used both for local consumption in the rain forest home countries and for exports.
Currently, a vast number of rain forest plants are also widely used in medicines. (13)
The “most lucrative” rain forest resources
There is virtually no doubt that, historically, logging had been the most lucrative business activity in the tropical rain forests.
This activity allows an accumulation of short-term profits without substantial long-term investments from logging companies.
In the most recent years, relative political and economic stability of rain forest countries allowed for the development of other extractive industries, such as mining and oil & gas . (14)
All these activities have inevitably caused, and are still causing, serious environmental damage.
Specifically, this leads to deforestation of pristine ancient rain forest ecosystems and an irreversible loss of valuable forest biodiversity.
C. Rain Forests As Unique Guarantors Of Local Environmental / Climatic Stability (15)
Apart from helping to regulate the global climatic conditions, rain forests also guarantee local environmental stability in several ways.
What happens if rain forests are removed?
1. Soil Erosion
Barren Soil
Barren Soil
Barren Soil
Rain forest soils are quite poor in nutrients, as virtually all of them are contained within the forest vegetation and animal biomass (thanks to the very efficient nutrient cycling within the forests).
So if a forest is cleared, the soil is fully exposed to heavy rainfalls that can easily wash away the topsoil and degrade the soil quality.
Once the topsoil is away, it leaves the deeper soil layers exposed to the air. The air hardens the deeper soil and degrades it even further.
Thus, such degraded soil can hardly be used for any productive activity.
2. Downstream silting
As the rainfalls wash away the rain forest soil, they can push such sediments to rivers, water reservoirs and irrigation systems and leave them silted.
This can cause contamination of drinkable water as well as interruption of operations of hydroelectric installations.
Higher river silt levels can also expose river-neighbouring areas to floods.
3. Downstream flooding
As a result of deforestation a larger proportion of rainfall, that would have otherwise been absorbed by the vegetation, is now directly transferred into river systems and may cause serious flooding in river-neighbouring areas.
4. Droughts
Rain forest vegetation stores a lot of moisture that evaporates and comes back as rainfall.
If this natural storage of moisture is destroyed, less rainfall is recycled and droughts ensue.
As an example, experts blame such rain forest clearance for recent droughts in Australia. (16)
5. Rain Forests Help Reduce the Amount of Solar Radiation Reflected Back Into the Atmosphere
Rainforest Absorbs Solar Radiation
Rainforest Absorbs Solar Radiation
Rainforests absorb large amounts of solar radiation
When solar radiation reaches the surface of the Earth, some of this radiation is absorbed by the planet and some of it is reflected back into space.
Some of this radiation reflected back will actually escape into space, and some of it will get trapped in the atmosphere.
A certain proportion of the radiation trapped in the atmosphere will then be re-reflected down to the planet and thus force the temperature to rise.
This is called a greenhouse effect , and it causes global warming.
So the importance of the rain forest vegetation from this point of view is that it helps reduce the amount of solar radiation reflected back into the atmosphere and therefore helps keep the temperatures stable.
Tropical Rain Forest Destruction - One of The Biggest Problems of Modern Times
Having considered all the services that tropical rainforests provide, it is really hard to overestimate their overall value to all of us inhabiting planet Earth.
Yet, all too often, financial gains take precedence over the urgent need for rain forest conservation.
Egbert Leigh Jr. refers to the tropical forest as “a victim of a spiritual crisis in humanity”. (17)
As an excellent illustrative example, find out how the Panama Canal construction almost a century ago affected this country's ecological situation by flooding many kilometers of its rainforests.
How very true this statement is!
Rain forest destruction is a very serious issue.
Virtually all the rain forest countries are developing countries and they are tempted to use their tropical resources for their economic and social development.
The fact that many of these countries have crippling amounts of foreign debt complicates the situation even further as these governments quite often resort to the use of precious forest reserves to repay their lenders.
Global Warming Earth Sweating
Global Warming Earth Sweating
Global warming may damage the rainforests
See here for a more detailed discussion of rain forest destruction .
But it is not only the structural destruction of rain forests that is a problem we have to deal with.
It is also on-going environmental pollution that seriously affects the health of these vulnerable ecosystems.
We discuss the problem of pollution and its impacts on the rain forests here.
To crown it all, the healthy functioning of rain forests may also be severely disrupted by global warming .
Prospects for the Future?
Not everything is doom and gloom though.
For example, the deforestation rate of the Amazon rain forest (the largest tropical fain forest in the world) during 2005–2006 was the lowest since 1991. (18)
People in many different countries of the world now recognise the real dangers of global warming and are actually expressing the willingness to pay higher bills to reverse this process. (19)
Year 2007 also saw the world’s special recognition of the climate change problem, as the Nobel Peace Prize for this year went to the United Nations’ Intergovernmental Panel on Climate Change (UN IPCC) and Al Gore Jr.: “for their efforts to build up and disseminate greater knowledge about man-made climate change”. (20)
So we should all put as much effort as possible to prevent further destruction of tropical rain forests and save our planet from a potential ecological disaster – we don’t have a choice!
Lim Wei Liang: As you realize that global warming IS REAL, opportunities and need both increase for rainforest conservation. Info has been out there for decades, but maybe the public eye has become so accustomed to the burning and clear-cutting pictures, it no longer really notices them.
Logging - much of it done illegally - is the most visible form of rainforest destruction.
Clear-cutting is usually the most profitable means of harvesting valuable timber, because the rainforest tends to be an "equal opportunity grower" with trees of high monetary value interspersed with what are seen as "junk" trees.
At least with logging, not everything is wasted, as happens when the forest is burned to clear it for pasture or other agriculture. Burning rainforests can be clearly seen from outer space , as this astronaut's photo of Mexico shows - what looks like white dots are actually fires.
But even with careful deforestation - selective logging - the roads that are built for logging access wind up being used for human activities that are further damaging to delicate ecosystems.
Why You Should Share Rainforest Conservation Info
Rainforests are crucial to the ecosystem of our planet. They have been described as the Earth's "lungs" or respiratory system. The massive numbers of trees and other plants absorb carbon dioxide (CO2), and then "breathe out" oxygen, which we need to survive.
We (humans and animals) breathe in the air around us, take in the oxygen, then throw off carbon dioxide as we exhale. This is a great arrangement, because everything balances out, if all is working as it should.
Unfortunately, the use of fossil fuels (carbon that has been stored underground for millennia, and is now being released) is dramatically increasing the world-wide levels of CO2. So just at the time we need all those trees in the rainforest the very most , we are destroying them through ignorance and greed.
Rainforest conservation info can mean the difference between a clear-cutting junk heap and a jungle paradise.
Rainforest conservation info can mean the difference between a clear-cutting junk heap and a jungle paradise.
Rainforests are also home to loads of wildlife and plant species, many of which have never even been documented. Many scientists believe the potential is huge for finding medical cures in these tropical regions.
As we destroy the forests, we also wipe out the indigenous cultures and people who have lived there for generations. Find extensive rainforest conservation info at Mongabay.com
What Can You Do to Help Preserve the Rainforests?
It's true that this a huge and terrible mess, but, short of going into the Amazon jungle and chaining yourself to a tree (not a really useful activity), there are many little things you can do to help save the rainforests.
Anything you accomplish that will prevent Global Warming will also help with rainforest conservation (info here) .
You can buy a tree, or purchase the timber rights on an acre of rainforest.
And of course there are many great non-profit organizations who urgently need your contributions. You can even trigger a donation to save the rainforest by simply clicking the mouse on your computer. http://www.greenhq.net/rainforest-conservation-info.html
Rainforests of the World
Wild and wondrous, rainforests extend from as far as Alaska and Canada to Latin America, Asia and Africa. They nurture thousands of plants and animals found nowhere else on Earth and provide life's essentials such as our medicines, food and water.
The Nature Conservancy is working around the world in places like Costa Rica's Osa Peninsula to protect rainforests, engaging local and indigenous communities in creative solutions that balance the needs of people with nature.
Why Should You Care About the Rainforest?
Besides providing food, water and air to the rest of the world, rainforests offer critical habitat for many of the Earth's most interesting and rare plants and animals. Read on for more [[rainforests/explore/facts.html|rainforest facts]]:
Temperate and tropical rainforests help regulate the Earth's temperature and weather patterns.
Rainforests provide jobs to surrounding communities.
Rainforests contain many of the essential plants used in the treatment of cancer.
Fifty percent of the world's plants and animals can be found in the rainforest.
The Nature Conservancy's Rainforests Work
The Nature Conservancy has launched many conservation programs to protect these vital forests and all the plants, animals and people that depend on them. Working in many of the world's most threatened forest systems, The Nature Conservancy has had many tangible and lasting successes:
Plant and animal diversity assessments of the coastal Amazon rainforest;
Training for national park guards in Bolivia;
Support for implementing rainforest protection projects in the Asia Pacific region;
Sustainable income-generating projects in Chile;
Effective park management in Panama and Costa Rica;
Scientific analysis of new protected areas within temperate rainforests in Canada; and
Since its beginning, our Adopt an Acre® program has protected hundreds of thousands of forested acres worldwide.
We are all part of this Earth. Invest in our future and the future of our planet. Be a steward of the rainforests.
When you make a gift to protect the rainforest , you'll help to ensure that the world’s most vital forests like the Osa are restored, protected and sustained for future generations.
Wei Liang: Here is another URL, from that website you can probably find out a lot of stuff and there are many links from that website too. ?http://rainforests.mongabay.com/0101.htm http://www.ias.ac.in/currsci/jul252008/216.pdf RESEARCH ARTICLES CURRENT SCIENCE, VOL. 216 95, NO. 2, 25 JULY 2008
*For correspondence. (e-mail: ravi@ces.iisc.ernet.in) Forest conservation, afforestation and
reforestation in India: Implications for
forest carbon stocks N. H. Ravindranath1,*, Rajiv Kumar Chaturvedi2 and Indu K. Murthy2 1Centre for Sustainable Technologies, and 2Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India This article presents an assessment of the implications
of past and current forest conservation and regeneration
policies and programmes for forest carbon sink in
India. The area under forests, including part of the
area afforested, is increasing and currently 67.83 mha
of area is under forest cover. Assuming that the current
trend continues, the area under forest cover is
projected to reach 72 mha by 2030. Estimates of carbon
stock in Indian forests in both soil and vegetation
range from 8.58 to 9.57 GtC. The carbon stock in existing
forests is projected to be nearly stable over the
next 25 year period at 8.79 GtC. However, if the current
rate of afforestation and reforestation is assumed
to continue, the carbon stock could increase from
8.79 GtC in 2006 to 9.75 GtC by 2030 – an increase of
11%. The estimates made in this study assume that
the current trend will continue and do not include
forest degradation and loss of carbon stocks due to
biomass extraction, fire, grazing and other disturbances.
Keywords: Afforestation, carbon stocks, conservation,
reforestation.
INDIA is a large developing country known for its diverse
forest ecosystems and is also a mega-biodiversity country.
Forest ecosystems in India are critical for biodiversity,
watershed protection, and livelihoods of indigenous and
rural communities. The National Communication of the
Government of India to the UNFCCC has reported1 that
the forest sector is a marginal source of CO2 emissions.
India has formulated and implemented a number of policies
and programmes aimed at forest and biodiversity
conservation, afforestation and reforestation. Further, India
has a goal2 to bring one-third of the geographic area under
forest and tree cover by 2012. All forest policies and
programmes have implications for carbon sink and forest
management. This article presents an assessment of the
implications of past and current forest conservation and
regeneration policies and programmes for forest carbon
sink in India. It also estimates the carbon stocks under
current trend scenario for the existing forests as well as
new area brought under afforestation and reforestation for
the period 2006–30.
We have primarily relied on published data from the
Ministry of Environment and Forests (MOEF), Government
of India (GOI); Food and Agricultural Organization
of United Nations (FAO), and Forest Survey of India
(FSI). We have used the Comprehensive Mitigation Analysis
Process (COMAP) model for projecting carbon stock
estimates. The article is based only on past trends from
1980 to 2005 and uses the assumption – ‘if the current trend
continues’. We feel that such an assumption is well justified
because, despite the increase in population and industrialization
during 1980–2005, forest area in India not
only remained stable but has marginally increased. This
is due to favourable policies and initiatives pursued by
GOI. We expect that India will not only keep pursuing
aggressive policies of afforestation and forest conservation,
but also go a step forward. A case in point is the
Prime Minister’s recently announced ‘6 mha greening
programme’. If the assumptions of continuation of current
rates of afforestation, forest conservation policies
and no significant degradation of forest carbon stocks are
changed, the future carbon stocks projected will also
change. Area under forests According to FSI, ‘all lands, more than one hectare in
area, with a tree canopy density of more than 10 per cent
are defined as Forest’. The total forest cover in India according
to the latest3 State of Forest Report 2003 is
67.83 mha and this constitutes 20.64% of the geographic
area. The distribution of area under very dense, dense and
open forest is given in Table 1. Dense forest dominates,
accounting for about half of the total forest cover. Tree
cover (which includes forests of less than 1 ha) is 9.99 mha
(3.04%). The total area under forest and tree cover is
77.82 mha, which is 23.68% of the geographic area (Table 1).
FAO4 defines forests as ‘Land spanning more than 0.5 ha
with trees higher than 5 m and a canopy cover of more
than 10%, or trees able to reach these thresholds in situ’.
And other woodlands as ‘Land not classified as “Forest”,
spanning more than 0.5 ha; with trees higher than 5 m RESEARCH ARTICLES CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 217 and a canopy cover of 5–10 per cent, or trees able to
reach these thresholds in situ; or with a combined cover
of shrubs, bushes and trees above 10 per cent. Both of
these categories do not include the land that is predominantly
under agricultural or urban land use’. According to
FAO, the area under forests and other wooded land in
India has increased from 63.93 mha in 1990 to 67.70 mha
in 2005. Thus FAO estimates do not significantly differ
from FSI estimates. Trends in area under forest and tree cover The FSI has been periodically estimating the forest cover
in India since 1987, using remote sensing techniques. The
forest cover reported5 for 1987 was 64.08 mha and according
to the latest assessment3 for 2003, the forest
cover is 67.83 mha. This indicates an increase in forest
cover of 3.75 mha over a period of 15 years (Figure 1). It
can be observed from Figure 1 that the forest cover in India
has nearly stabilized and has been increasing marginally
over the years3,5–12. FSI has included the tree cover in
the 2001 and 2003 assessments3,6, in addition to forest
cover. The area under tree cover reported is also found to
be marginally increasing (Figure 1). Afforestation and reforestation programmes India has been implementing an aggressive afforestation
programme. The country initiated large-scale afforestation
under the social forestry programme starting in the Table 1. Status of forest cover in India3,4 Per cent
Tree crown class Area (mha) geographic area
Very dense forest (>70%) 5.13 1.56
Dense forest (40–70%) 33.93 10.32
Open forest (10–40%) 28.78 8.76
Mangroves 0.45 0.14
Total forest cover 67.83 20.64
Tree cover 9.99 3.04
Total 77.82 23.68
Forest cover according to FAO 67.7 – 0
10
20
30
40
50
60
70
80
90
1987 1989 1991 1993 1995 1997 1999 2001 2003
Forest and tree cover (Mha)
Forest cover Tree cover Figure 1. Trends in area under forest and tree cover3,5–12. early 1980s. Figure 2 shows the progress of afforestation
in India for the period 1951–2005. It can be seen from
Figure 2 that the cumulative area afforested in India during
the period 1980–2005 is about 34 mha, at an average
annual rate2 of 1.32 mha2. This includes community woodlots,
farm forestry, avenue plantations and agro-forestry.
Afforestation and reforestation in India are being carried
out under various programmes, namely social forestry
initiated in the early 1980s, Joint Forest Management
Programme initiated in 1990, afforestation under National
Afforestation and Eco-development Board (NAEB) programmes
since 1992, and private farmer and industryinitiated
plantation forestry. Future trends in area under forests and
afforestation The projections for area under forest as well as area afforested
are based on current trends or what is generally
termed the ‘current trend scenario’. The current trend scenario
is based on the past, current and short-term afforestation
plans. The projections exclude the tree cover
component as reported in 2001 and 2003 by the FSI. Projections for area under forest cover based on
current trend scenario The forest cover is projected up to 2030, based on the
past and current trends, as reported by the periodic re- Figure 2. Cumulative area afforested2 during 1951–2005. Projected trend in forest cover under the current trend scenario3,5–
. RESEARCH ARTICLES CURRENT SCIENCE, VOL. 218 95, NO. 2, 25 JULY 2008 ports of the FSI. It can be observed from Figure 3 that the
forest cover will continue to increase all the way up to
2030. The forest cover is projected to reach 72.19 mha by
2030, assuming that the current trend scenario will continue. Projected afforestation rates based on current
trends The long-term average annual rate of afforestation over
the period 1980–2005 is 1.32 mha. Assuming the average
rate2 of 1.32 mha for the period 2006–30, the total area
that would be afforested is 33 mha. The cumulative area
afforested would be 70.5 mha by 2030 (Figure 4). This
includes short- and long-rotation plantation forestry as
well as natural regeneration. It is important to note that
some of the afforested area, particularly short-rotation
plantations, is likely to be periodically harvested and replanted
or left for coppice regrowth. Carbon stocks in forests The forest sector could be a source or a sink of carbon.
Forest carbon stock includes biomass and soil carbon
pools. Biomass carbon can be further disaggregated into
aboveground and belowground biomass and dead organic
matter. Change in forest carbon stock between two time
periods is an indicator of the net emissions of CO2 from
the sector. Carbon stocks are estimated and projected for
the period 2005–30. Methodology The COMAP model13 is a set of versatile models with the
ability to analyse the mitigation potential as well as costeffectiveness
of diverse activities such as forest conservation
(e.g. Protected Areas and halting forest conversion), Figure 4. Projected afforestation under the current trend scenario. natural regeneration (with no logging) and afforestation/
reforestation through plantation forestry, including
short- as well as long-rotation forestry (with logging or harvesting).
Assessment of mitigation activities using the COMAP
model would involve consideration of the following: • Land availability for different mitigation activities
during different years. • Wood product demand and supply to ensure that socioeconomic
demands are met with and real additional
mitigation is feasible. • Developing a baseline or current trend scenario to enable
estimation of incremental carbon mitigation. • Developing a mitigation scenario incorporating the
extent of area to be covered for meeting different
goals.
Data required for assessing different activities: The data
required for assessing the mitigation potential of afforestation
and reforestation include land area-related information,
baseline carbon density (tC/ha) in above-ground
vegetation and soil, rotation period, above-ground woody
biomass accumulation rate (tC/ha/yr), soil carbon enhancement
rate (tC/ha/yr), and cost and benefit flows. Input
data were obtained from the literature14,15.
Outputs of the COMAP model: These include mitigation
potential estimates per ha and aggregate tonnes of
carbon benefit, annual carbon stocks, carbon stocks for a
given year such as 2008 and 2012 and cumulative over a
period, and cost-effectiveness parameters. Carbon stock estimates Estimates for the forest carbon stocks, including biomass
and soil carbon from previous studies are given in Figure
5. According to an earlier estimate by Richards and Flint16, 0
2000
4000
6000
8000
10000
12000
1880
1980
1986
1986
1994
2005
Carbon stock (MtC)
Biomass carbon Soil carbon Figure 5. Trends in carbon stock estimates for Indian forests15–19. RESEARCH ARTICLES CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 219 0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030
Carbon stock (MtC)
Forest Short rotation Long rotation Natural regeneration 0
2000
4000
6000
8000
10000
12000
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030
Carbon stock (MtC)
Soil carbon Biomass carbon Figure 6. Projected forest carbon stocks. a, Under the current trend scenario for existing forests and area afforested (short- and
long-rotation and natural regeneration). b, According to biomass and soil carbon. the biomass carbon stock in Indian forests was 7.94 MtC
during 1880. This study does not provide soil carbon estimates.
Further estimates by the same authors for 1980
showed that forest biomass carbon stock had declined by
nearly half over a period of 100 years. Estimates17–19 of
forest carbon stock, including biomass and soil carbon for
the year 1986, are in the range 8.58–9.57 GtC. According
to a latest estimate by FAO4, total forest carbon stock in
India is 10.01 GtC. Thus, the carbon stocks in Indian forests
have not declined, and in fact seem to have increased,
over a period of 20 years (1986–2005). Forest soil carbon
accounts for over 50% of the total forest carbon stock. Carbon stock projections under current trend
scenario Carbon stock projections for the existing forests as well
as new area brought under afforestation and reforestation
for the current trend scenario are made for the period
2006–30. The carbon stock projections are made using
the COMAP model. The forest cover data were obtained
from the projections made using the FSI area trends (Figure
3) and afforestation rates were obtained from the past
trends (average annual rate of 1.32 mha). The biomass
and soil carbon stock and growth rates were obtained from
published literature14,15. The afforestation rate of 1.32 mha/
annum was allocated to short- and long-rotation and natural
regeneration at 63.7, 32.2 and 4.1% respectively,
based on the previous years’ trend12.
The carbon stock projections for the period 2006–30
are given in Figure 6. The carbon stock in the existing forests
is projected to be nearly stable over the 25-year period
at 8.79 GtC (Figure 6 a). When afforestation and
reforestation is included, the carbon stock is projected to
increase from 8.79 GtC in 2006 to 9.75 GtC by 2030,
about 11% increase (Figure 6 a). It is important to note
that COMAP model accounts for harvests and the resulting
emissions. Thus, Indian forests will be a net sink over
the next 25 years. Figure 6 b shows the dominance of soil
carbon in the total forest carbon stock. Factors contributing to stabilization of carbon
stocks in Indian forests India is one of the few countries where deforestation rate
has been reduced and regulated and forest cover nearly
stabilized, unlike most other tropical countries. Further,
the projections of carbon stocks for the period 2006–30
showed that the carbon stock will increase. Thus, it is
important to understand the likely factors contributing to
the observed and projected stabilization of forest cover as
well as forest carbon stocks in India. The factors include
legislations, forest conservation and afforestation programmes,
and community awareness and participation. Forest Conservation Act, 1980 This Act is one of the most effective legislations contributing
to reduction in deforestation. This was enacted to
reduce indiscriminate diversion of forest land for nonforestry
purposes, and to help regulate and control the recorded
forest land-use changes. Compensatory afforestation According to Forest Conservation Act, 1980, when after
careful consideration forest land is released for any infrastructure
projects, it is mandatory for compensatory plantations
to be raised on an equivalent non-forested land or
equal to double the area on degraded forestland. Wildlife parks and protected area In India, 15.6 mha is Protected Area, where all human intervention
or extraction is banned. Afforestation India has been implementing large-scale afforestation/
reforestation since 1980 under social forestry, Joint Forest RESEARCH ARTICLES CURRENT SCIENCE, VOL. 220 95, NO. 2, 25 JULY 2008 Management, silvi-pasture, farm forestry and agro-forestry
programmes, covering over 30 mha. This may have reduced
pressure on the forests. National Forest Policy, 1988 It envisages people’s participation in the development and
protection of forests. The basic objective of this policy is
to maintain environmental stability through preservation
of forests as a natural heritage. Joint Forest Management (JFM), 1990 The Forest Policy 1988 set the stage for participatory forest
management in India. The JFM programme recognized
the rights of the protecting communities over forest lands.
The local communities and the Forest Department jointly
plan and implement forest regeneration programmes and
the communities are rewarded for their efforts in protection
and management. The total area covered under the JFM
programme is over 15 mha. This has enabled protection
of existing forests, regeneration of degraded forests and
raising of forest plantations, potentially contributing to
conservation of existing forests and carbon stocks. Significance of stabilization of forest carbon
stocks in India India is one of the few countries in the world, particularly
among the tropical countries, where carbon stock in forests
has stabilized or is projected to increase. This has implications
for reducing the carbon emissions from forest sector,
potentially contributing to stabilization of CO2 concentration
in the atmosphere. This Indian achievement is significant
due to the following. High population density and low per capita
forest area India is a large developing country with a population
density of 363 persons/km2. Even more significantly, the
forest area per capita is only 0.06 ha, compared to the world
average of 0.62 ha/capita and Asian average of 0.15 ha/
capita. A comparison of key developing countries and
Western European countries4 is provided in Table 2. Forests
and wooded land area per 1000 population in Germany
and France is nearly two and five times that of India.
Similarly, forest and wooded land in other major developing
countries such as Brazil, China and Indonesia are also
higher by 3 to 40 times, as compared to India. Low deforestation rate compared to other
developing countries According to the Global Forest Resources Assessment4,
countries such as India and China are experiencing an increase
in forest area since 1990 (Table 3). However, majority
of the other tropical countries with large area under
forests are experiencing deforestation on a significant
scale since 1990 (Table 3). Majority of the countries (42–
65%) are experiencing reduction in forest area or net deforestation4 (Table 4). High dependence of human population on forests In India, nearly 196,000 villages are in the forests or on the
forest fringes. Fuelwood is a dominant source of cooking
energy for the rural population with forests contributing
significantly to this. Apart from fuelwood, village communities
depend on forests for small timber, bamboo and nontimber
forest products. High livestock density India accounts for 2.3% of the world’s geographic area,
but accounts for 15% of the global livestock population.
The cattle (cows, bullocks and buffaloes) population density
is nearly one per hectare. When sheep and goats are
included along with cattle, the livestock population density
further increases to 1.5 per hectare. However, if only
forest land is considered, the livestock density is 7 per
hectare, which is among the highest in the world. Table 2. Comparison of total forest area and forest area/1000 population4 Total area under Forest and wooded
Population Forest area Other wooded forest and wooded land (ha/1000
Country (million) (‘000 ha) land (‘000 ha) land (‘000 ha) population)
India 1079 67,701 4110 71,811 66
China 1326 197,290 87,615 284,905 215
Brazil 178 477,698 0 477,698 2673
Indonesia 217 88,495 0 88,495 406
Germany 82 11,076 0 11,076 134
United Kingdom 59 2845 20 2865 48
France 59 15,554 1708 17,262 287 RESEARCH ARTICLES CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 221 Table 3. Comparison of forest area change and deforestation (in ‘000 ha) in other major developing countries4 Net annual change in Area under forest Net annual change in
forest area (‘000 ha) (‘000 ha) forest area (‘000 ha)
Key developing
Region 1990 to 2000 2000 to 2005 countries 1990 2000 2005 1990–2000 2000–2005
Asia –792 1003 China 157,141 177,001 197,290 1986 4058
India 63,939 67,554 67,701 362 29
Indonesia 116,567 97,852 88,495 –1872 –1871
Malaysia 22,376 21,591 20,890 –78 –140
Philippines 10,574 7949 7162 –262 –157
Africa –4375 –4040 Sudan 76,381 70,491 67,546 –589 –589
Zambia 49,124 44,676 42,452 –445 –445
UR Tanzania 41,441 37,318 35,257 –412 –412
Nigeria 17,234 13,137 11,089 –410 –410
South Africa 9203 9203 9203 0 0
South America –3802 –4251 Brazil 520,027 493,213 477,698 –2681 –3103
Argentina 35,262 33,770 33,021 –149 –150
Mexico 69,016 65,540 64,238 –348 –260
Peru 70,156 69,213 68,742 –94 –94
Columbia 61,439 60,963 60,728 –48 –47 Table 4. Countries with positive, negative and zero or marginal annual rate of change in forest area4 Countries with negative Countries with positive Countries with zero net Countries with no
Total number rate of net annual change rate of net annual change annual change in forest significant net annual change
Region of countries in forest area (2000–05) in forest area (2000–05) area (2000–05) in forest area (2000–05)
Asia 48 20 13 12 3
Africa 58 38 8 8 4
South America 15 8 2 3 2 (not available) Dominance of agrarian economy Rural areas in India are characterized by large dependence
of the population on land resources, particularly
cropland and forest land, leading to more human pressure
on land. Implications of Indian forest conservation and
development programmes and policies for global
change India is a large developing country with a high population
density and low forest area per capita. The livestock
population density is among the highest in the world. Further,
nearly 70% of the population residing in rural areas
depends on forest and other biomass resources for fuelwood,
timber and non-timber forest products for its energy
needs and livelihood. In such a socio-economic
scenario, one would have expected the forest area to decline,
leading to large emissions of CO2 from the forest sector.
The analysis of forest cover, afforestation and reforestation
has shown that the forest cover has stabilized in the
past 15 years (64–67 mha). Projections under the current
trend scenario indicate that the forest cover is likely to
increase in the period 2006–30. Further, model-based
projections of carbon stocks in the Indian forest sector
show a likely increase (from 8.79 GtC in 2005 to 9.75 GtC
in 2030). This is a significant achievement for a developing
country such as India, despite high human and livestock
population density, high dependence of rural
communities on forests for biomass resources and low per
capita forest area. The factors contributing to the current
and projected trends of stable or increasing carbon stocks
in the forests are progressive and effective forest conservation
legislations, afforestation and reforestation programmes
and community participation in forest protection,
regeneration and management.
The progressive conservation-oriented forest policies
and afforestation programmes are contributing to reduction
in CO2 emissions to the atmosphere, stabilization of
carbon stocks in forests and conservation of biodiversity.
Thus, the Indian forest sector is projected to keep making
positive contributions to global change and sustainable
development. This projected estimate and conclusion excludes
any potential decline in forest carbon stocks due to
forest conversion, forest degradation, biomass extraction,
fire, etc. RESEARCH ARTICLES CURRENT SCIENCE, VOL. 222 95, NO. 2, 25 JULY 2008
1. Ministry of Environment and Forests, India’s Initial National
Communication to UNFCCC (NATCOM), New Delhi, 2004;
available at http://www.natcomindia.org/natcomreport.htm 2. http://envfor.nic.in/nfap/, accessed on 11 July 2007.
3. Forest Survey of India, State of Forest Report 2003, Ministry of
Environment and Forests, Dehra Dun.
4. FAO, State of the World’s Forests, Rome, 2005.
5. Forest Survey of India, State of Forest Report 1987, Ministry of
Environment and Forests, Dehra Dun.
6. Forest Survey of India, State of Forest Report 2001, Ministry of
Environment and Forests, Dehra Dun.
7. Forest Survey of India, State of Forest Report 1989, Ministry of
Environment and Forests, Dehra Dun.
8. Forest Survey of India, State of Forest Report 1991, Ministry of
Environment and Forests, Dehra Dun.
9. Forest Survey of India, State of Forest Report 1993, Ministry of
Environment and Forests, Dehra Dun.
10. Forest Survey of India, State of Forest Report 1995, Ministry of
Environment and Forests, Dehra Dun.
11. Forest Survey of India, State of Forest Report 1997, Ministry of
Environment and Forests, Dehra Dun.
12. Forest Survey of India, State of Forest Report 1999, Ministry of
Environment and Forests, Dehra Dun.
13. Sathaye, J. and Meyers, S., Greenhouse Gas Mitigation Assessment:
A Guidebook, Kluwer, Dordrecht, The Netherlands, 1995.
14. Ravindranath, N. H. et al., Methodological Issues in forestry mitigation
projects: A case study of Kolar district. Miti. Adap. Strat.
Global Change, 2007, 12, 1077–1098.
15. Ravindranath, N. H., Sudha, P. and Sandhya, R., Forestry for sustainable
biomass production and carbon sequestration in India. Miti. Adap. Strat. Global Change, 2001, 6, 233–256.
16. Richards, J. F. and Flint, E. P., Historic land use and carbon estimates
for South and Southeast Asia 1880–1980. ORNL/CDIAC-
61, NDP-046, Oak Ridge National Laboratory, Tennessee, USA,
1994.
17. Ravindranath, N. H., Somashekhar, B. S. and Gadgil, M., Carbon
flows in Indian forests. Climate Change, 1997, 35, 297–320.
18. Chhabra, A. and Dadhwal, V. K., Assessment of major pools and
fluxes of carbon in Indian forests. Climate Change, 2004, 64, 341–
360.
19. Haripriya, G. S., Carbon budget of the Indian forest ecosystem. Climate
Change, 2003, 56, 291–319.
ACKNOWLEDGEMENTS. We thank the MOEF, GOI for supporting
this project as well as climate change research activities at the Centre
for Ecological Sciences, Indian Institute of Science, Bangalore. We
also thank Jayant Sathaye and Ken Andrasko for their support in our
climate change research over the years.
Received 12 July 2007; revised accepted 22 May 2008 Erratum Sago starch: An economical substitute for in vitro primary screening of starch utilizing microorganisms R. B. Binky, R. Saikiran, S. Tushar, P. Umesh, J. Yogesh and A. N. Syed
[Curr. Sci., 2007, 93, 459–461]
Line 1, para 2, 2nd column should have been:
1. Successful use of isabgol derived from Plantago ovata seeds, gum katira exuded from Cochlospermum religiosum bark and guar gum from endosperm of Cyamopsis tetragonoloba as gelling agent has been reported for microbial
culture media3,6,7.
2. Nene, Z. L. in ref. 6 should have been Nene, Y. L.
We regret the error.
A '''tropical rainforest''' is an ecosystem usually found around the equator. They are common in Asia, Australia, Africa, South America, Central America, Mexico and on many of the Pacific Islands. Within the World Wildlife Fund's biome classification, tropical rainforests are considered a type of tropical wet forest (or tropical moist broadleaf forest) and may also be referred to as ''lowland equatorial evergreen rainforest''. Minimum normal annual rainfall between convert|1750|mm|in and convert|2000|mm|in occurs in this climate region. Mean monthly temperatures exceed convert|18|C|F during all months of the year.[1] Rainforests are home to half of all the living animal and plant species on the planet.<ref name="MI">The Regents of the University of Michigan. [http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/rainforest/rainforest.html The Tropical Rain Forest.] Retrieved on 2008-03-14.</ref> Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[2] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[3] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[4]
Characteristics
The rainforests are home to more species or populations than all other biomes combined. 82% of the world's biodiversity are found in tropical rainforests.[5] The leafy tops of tall trees - extending from 50 to 85 meters above the forest floor - forms an understory. Organic matter that falls to the forest floor quickly decomposes, and the nutrients are recycled.
Rainforests are characterized by high rainfall. This often results in poor soils due to leaching of soluble nutrients. Oxisols, as are the soils of many seasonally flooded forests, which are annually replenished with fertilesilt.
Tropical rain forests have been subjected to heavy logging and agricultural clearance throughout the 20th century, and the area covered by rainforests around the world is rapidly shrinking.[6][7]
Rainforests are also often called the "Earth's lungs," however there is no scientific basis for such a claim as tropical rainforests are known to be essentially oxygen neutral, with little or no net oxygen production.[8][9] rain forest in Peru]]
Tall, broad-leaved evergreen trees are the dominant plants, forming a leafy canopy over the forest floor. Taller trees, called emergents, may rise above the canopy. The upper portion of the canopy often supports a rich flora of epiphytes, including orchids, bromeliads, mosses, and lichens, who live attached to the branches of trees. The undergrowth or understory in a rainforest is often restricted by the lack of sunlight at ground level, and generally consists of shade-tolerant shrubs, herbs, ferns, small trees, and large woody vines which climb into the trees to capture sunlight. The relatively sparse under story vegetation makes it possible for people and other animals to walk through the forest. In deciduous and semi-deciduous forests, or forests where the canopy is disturbed for some reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called jungle.
The temperature ranges from 15 to 50 °C and 125 to 660 cm of rainfall yearly.
Layers
The rainforest is divided into five different parts, each with different plants and animals, adapted for life in the particular area. These are: the floor layer, the shrub layer, the undercanopy layer, the canopy layer and the emergent layer. Only the emergent layer is unique to tropical rainforests, while the others are also found in temperate rainforests.
The emergent layer contains a small number of very large trees which grow above the general canopy, reaching heights of 45-55 m, although on occasion a few species will grow to 70 m or 80 m tall. They need to be able to withstand the hot temperatures and strong winds. Eagles, butterflies, bats and certain monkeys inhabit this layer.
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Canopy - This is the primary layer of the forest and forms a roof over the two remaining layers. Most canopy trees have smooth, oval leaves that come to a point. It's a maze of leaves and branches. Many animals live in this area since food is abundant. Those animals include: snakes, toucans and tree frogs.
Under canopy - Little sunshine reaches this area so the plants have to grow larger leaves to reach the sunlight. The plants in this area seldom grow to 12 feet. Many animals live here including jaguars, red-eyed tree frogs and leopards. There is a large concentration of insects here.
Shrub layer/forest floor - This layer is very dark. Almost no plants grow in this area, as a result. Since hardly any sun reaches the forest floor things begin to decay quickly. A leaf that might take one year to decompose in a regular climate will disappear in 6 weeks. Giant anteaters live in this layer.
Human uses
Habitation
Tropical rainforests are unable to support human populations.<ref name="Bailey">Bailey, R.C., Head, G., Jenike, M., Owen,B., Rechtman, R., Zechenter, E., 1989 "Hunting and gathering in tropical rainforest: is it possible." American Anthropologist, 91:1 59-82</ref> Food resources within the forest are extremely dispersed due to the high biological diversity and what food does exist is largely restricted to the canopy and requires considerable energy to obtain. Some groups of hunter-gatherers have exploited rainforest on a seasonal basis but dwelt primarily in adjacent savanna and open forestenvironments where food is much more abundant. Other peoples described as rainforest dwellers are hunter-gatherers who subsist in large part by trading high value forest products such as hides, feathers, and honey with agricultural people living outside the forest.<ref name="Bailey"/>
Conversion to agricultural land
With the invention of agriculture humans were able to clear sections of rainforest to produce crops, converting it to open farmland. Such people, however, obtain their food primarily from farm plots cleared from the forest <ref name="Bailey"/>[10] and hunt and forage within the forest to supplement this.
Agriculture on formerly forested land is not without difficulties. Rainforest soils are often thin and leached of many minerals, and the heavy rainfall can quickly leach nutrients from area cleared for cultivation. People such as the Yanomamo of the Amazon, utilise slash-and-burn agriculture to overcome these limitations and enable them to push deep into what were previously rainforest environments. However, these are not rainforest dwellers, rather they are dwellers in cleared farmland<ref name="Bailey"/>[11] that make forays into the rainforest and up to 90% of the typical Yanamomo diet comes from farmed plants.[12]
Cultivated foods and spices
Coffee, chocolate, banana, mango, papaya, macadamia, avocado, and sugarcane all originally came from tropical rainforest and are still mostly grown on plantations in regions that were formerly primary forest. In the mid-1980s and 90s, 40 million tons of bananas were consumed worldwide each year, along with 13 million tons of mangoes. Central American coffee exports were worth US$3 billion in 1970. Much of the genetic variation used in evading the damage caused by new pests is still derived from resistant wild stock. Tropical forests have supplied 250 cultivated kinds of fruit, compared to only 20 for temperate forests. Forests in New Guinea alone contain 251 tree species with edible fruits, of which only 43 had been established as cultivated crops by 1985.[13]
Pharmaceutical and biodiversity resource
Tropical rainforests are called "the world's largest pharmacy"cn because of the large amount of natural medicines discovered in rainforests that are derived from rainforest plants. For example, rain forests contain the "basic ingredients of hormonal contraception methods, cocaine, stimulants, and tranquilizing drugs" (Banks 36)cn. Curare (a paralyzing drug) and quinine (a malaria cure) are also found there.
Tourism
Tourism in tropical rainforests has increased over the years having both positive and negative effects.Fact|date=September 2008 People travel both nationally and internationally to experience rain forests firsthand.
Positive Impacts
Despite the negative effects of tourism in the tropical rainforests, there are also several important positive effects.
*An increase in tourism has increased economic support, allowing more revenue to go into the protection of the habitat. Tourism can contribute directly to the conservation of sensitive areas and habitat. Revenue from park-entrance fees and similar sources can be utilised specifically to pay for the protection and management of environmentally sensitive areas. Revenue from taxation and tourism provides an additional incentive for governments to contribute revenue to the protection of the forest.
*Tourism also has the potential to increase public appreciation of the environment and to spread awareness of environmental problems when it brings people into closer contact with the environment. Such increased awareness can induce more environmentally conscious behavior. Tourism has had a positive effect on wildlife preservation and protection efforts, notably in Africa but also in South America, Asia, Australia, and the South Pacific.[14]
''Annals of Botany'' <ref name=aob>cite web
| last = Oxford University Press
| first =
| authorlink =
| coauthors =
| title = Annals of botany
| work =
| publisher =
| date =
| url = http://aob.oxfordjournals.org/
| format =
| doi =
| accessdate = 20 January
| accessyear = 2009 </ref>
T he world's tropical forests circle the globe in a ring around the Equator They are surprisingly diverse, ranging from lush rain forests to dry savannas and containing millions of species of plants and animals (fig. 1). Tropical forests once covered some 15.3 billion acres (6.2 billion ha). In recent times, however, they have been cut at a rapid rate to make room for agriculture and to obtain their many valuable products. Between 1985 and 1990, 210 million acres (85 million ha) of tropical forests were destroyed.
This guide shows how modern forest practices can help stem the tide of forest destruction while providing valuable forest products for people. The tropical forests of Puerto Rico, which were abused for centuries, were badly depleted by the early 1900's. Widespread abandonment of poor agricultural lands has allowed natural reforestation and planting programs to create a patchwork of private, Commonwealth, and Federal forests across the land (fig. 2). The most frequent example in this publication is the Luquillo Experimental Forest, which could be a model for protecting and managing tropical forests worldwide. About half of all the world's forests are in the Tropics, the area between the Tropic of Cancer and the Tropic of Capricorn. This region may be best known for its rain forests - lush, steamy jungles with towering trees, epiphytes, and dense under stories of smaller trees, shrubs, and vines.
Tropical forests are surprisingly diverse. In addition to rain forests, there are mangroves, moist forests, dry forests, and savannas. Such classifications, however, give only a slight indication of the diversity of tropical forests. One study by the Food and Agriculture Organization (FAO) of the United Nations, which considered 23 countries in tropical America, 37 in tropical Africa, and 16 in tropical Asia, identified dozens of types of tropical forests: open and closed canopy forests, broadleaved trees and conifer forests , closed forests and mixed forest grasslands, and forests where agriculture has made inroads. Rain Forests**
The largest remaining areas of tropical rain forests are in Brazil, Congo, Indonesia, and Malaysia. Precipitation generally exceeds 60 inches (150 cm) per year and may be as high as 400 inches (1000 cm). Lowland rain forests are among the
fig3.gif (29562 bytes)
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world's most productive of plant communities. Giant trees may tower 200 feet (60 m) in height and support thousands of other species of plants and animals. Montane (mountain) rain forests grow at higher elevations where the climate is too windy and wet for optimum tree growth.
Mangrove forests grow in the swampy, intertidal margin between sea and shore and are often considered part of the rain forest complex. The roots of mangrove trees help stabilize the shoreline and trap sediment and decaying vegetation that contribute to ecosystem productivity (fig. 3). Dry Forests
Large areas of tropical dry forests are found in India, Australia, Central and South America, the Caribbean, Mexico, Africa, and Madagascar. Dry forests receive low rainfall amounts, as little as 20 inches (50 cm) per year, and are characterized by species well adapted to drought. Trees of dry tropical forests are usually
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smaller than those in rain forests, and many lose their leaves during the dry season. Although they are still amazingly diverse, dry forests often have fewer species than rain forests.
Savanna is a transitional type between forest and grassland. Trees are often very scattered and tend to be well adapted to drought and tolerant of fire and grazing. If fire is excluded, trees eventually begin to grow and the savanna is converted to dry forest. With too much fire or grazing, dry forest becomes savanna (fig. 4). This vegetation type has fewer species of trees and shrubs but more grasses and forbs than other forest types in the Tropics.
All forests have both economic and ecological value, but tropical forests are especially important in global economy. These forests cover less than 6 percent of the Earth's land area, but they contain the vast majority of the world's plant and animal genetic resources. The diversity of life is astonishing. The original forests of Puerto Rico, for example, contain more than 500 species of trees in 70 botanical families. By comparison, temperate forests have relatively few. Such diversity is attributed to variations in elevation, climate, and soil, and to the lack of frost.
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There is also diversity in other life forms: shrubs, herbs, epiphytes, mammals, birds, reptiles, amphibians, and insects. One study suggests that tropical rain forests may contain as many as 30 million different kinds of plants and animals, most of which are insects (fig. 5). Wood and Other Products
Tropical forests provide many valuable products including rubber, fruits and nuts, meat, rattan, medicinal herbs, floral greenery, lumber, firewood, and charcoal. Such forests are used by local people for subsistence hunting and fishing. They provide income and jobs for hundreds of millions of people in small, medium, and large industries.
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Tropical forests are noted for their beautiful woods (fig. 6). Four important commercial woods are mahogany, teak, melina, and okoume. Honduras mahogany (Swietenia macrophylla), grows in the Americas from Mexico to Bolivia. A strong wood of medium density, mahogany is easy to work, is long lasting, and has good color and grain. It is commonly used for furniture, molding, paneling, and trim. Because of its resistance to decay, it
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is a popular wood used in boats. Teak (Tectona grandis) is native to India and Southeast Asia. Its wood has medium density, is strong, polishes well, and has a warm yellow-brown color. Also prized for resistance to insects and rot, teak is commonly used in cabinets, trim, flooring, furniture, and boats (fig. 7). Melina (Gmelina arborea) grows naturally from India through Vietnam. Noted for fast growth, melina has light colored wood that is used mainly for pulp and particleboard, matches and carpentry. Okoume (Aucoumea klaineana) is native to Gabon an the Congo in west Africa. A large fast-growing tree, the wood has mod erately low density, good strength-to density ratio, and low shrinkage during drying. It is commonly use( for plywood, paneling, interior fur niture parts, and light construction. Other Economic Values
Tropical forests are home for tribal hunter-gatherers whose way of life has been relatively unchanged for centuries. These people depend on the forests for their livelihood. More than 2.5 million people also live in areas adjacent to tropical forests. They rely on the forests for their water, fuelwood, and other resources and on its shrinking land base for their shifting agriculture. For urban dwellers, tropical forests provide water for domestic use and hydroelectric power. Their scenic beauty, educational value, and opportunities for outdoor recreation support tourist industries.
Many medicines and drugs come from plants found only in tropical rain forests. Some of the best known are quinine, an ancient drug used for malaria; curare, an anesthetic and muscle relaxant used in surgery; and rosy periwinkle, a treatment for Hodgkin's disease and leukemia. Research has identified other potential drugs that may have value as contraceptives or in treating a multitude of maladies such as arthritis, hepatitis, insect bites, fever, coughs, and colds. Many more may be found. In all, only a few thousand species have been evaluated for their medicinal value.
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In addition, many plants of tropical forests find uses in homes and gardens: ferns and palms, the hardy split-leaf philodendron, marantas, bromeliads, and orchids (fig. 8), to name just a few. Environmental Benefits
Tropical forests do more than respond to local climatic conditions; they actually influence the climate. Through transpiration, the enormous number of plants found in rain forests return huge amounts of water to the atmosphere, increasing humidity and rainfall, and cooling the air for miles around. In addition, tropical forests replenish the air by utilizing carbon dioxide and giving off oxygen. By fixing carbon they help maintain the atmospheric carbon dioxide levels low and counteract the global "greenhouse" effect.
Forests also moderate stream flow. Trees slow the onslaught of tropical downpours, use and store vast quantities of water, and help hold the soil in place. When trees are cleared, rainfall runs off more quickly, contributing to floods and erosion.
Before the dawn of agriculture approximately 10,000 years ago, forests and open woodland covered about 15.3 billion acres (6.2 billion ha) of the globe. Over the centuries, however, about one-third of these natural forests has been destroyed. According to a 1982 study by FAO, about 27.9 million acres (11.3 million ha) of tropical forests are cut each year-an area about the size of the States of Ohio or Virginia. Between 1985 and 1990, an estimated 210 million acres (85 million ha) of tropical forests were cut or cleared. In India, Malaysia, and the Philippines, the best commercial forests are gone, and cutting is increasing in South America. If deforestation is not stopped soon, the world will lose most of its tropical forests in the next several decades. Reasons for Deforestation
Several factors are responsible for deforestation in the Tropics: clearing for agriculture, fuelwood cutting, and harvesting of wood products. By far the most important of these is clearing for agriculture. In the Tropics, the age-old practice of shifting, sometimes called "slash-and-burn," agriculture has been used for centuries. In this primitive system, local people cut a small patch of forest to make way for subsistence farming. After a few years, soil fertility declines and people move on, usually to cut another patch of trees and begin another garden.
In the abandoned garden plot, the degraded soil at first supports only weeds and shrubby trees. Later, soil fertility and trees return, but that may take decades. As population pressure increases, the fallow (rest) period between cycles of gardening is shortened, agricultural yields decrease, and the forest region is further degraded to small trees, brush, or eroded savanna.
Conversion to sedentary agriculture is an even greater threat to tropical forests. Vast areas that once supported tropical forests are now permanently occupied by subsistence farmers and ranchers and by commercial farmers who produce sugar, cocoa, palm oil, and other products.
In many tropical countries there is a critical shortage of firewood. For millions of rural poor, survival depends on finding enough wood to cook the evening meal. Every year more of the forest is destroyed, and the distance from home to the forest increases. Not only do people suffer by having to spend much of their time in the search for wood, but so does the land. Damage is greatest in dry tropical forests where firewood cutting converts forests to savannas and grasslands.
The global demand for tropical hardwoods, an $8-billion-a-year industry, also contributes to forest loss. Tropical forests are usually selectively logged rather than clear-cut. Selective logging leaves the forest cover intact but usually reduces its commercial value because the biggest and best trees are removed. Selective logging also damages remaining trees and soil, increases the likelihood of fire, and degrades the habitat for wildlife species that require large, old trees-the ones usually cut. In addition, logging roads open up the forests to shifting cultivation and permanent settlement.
In the past, logging was done primarily by primitive means-trees were cut with axes and logs were moved with animals such as oxen. Today the use of modern machinery--chain saws, tractors, and trucks -makes logging easier, faster, and potentially more destructive. Endangered Wildlife
Forests are biological communities-complex associations of trees with other plants and animals that have evolved together over millions of years. Because of the worldwide loss of tropical forests, thousands of species of birds and animals are threatened with extinction. The list includes many unique and fascinating animals, among them the orangutan, mountain gorilla, manatee, jaguar, and Puerto Rican parrot. Although diverse and widely separated around the globe, these specles have one important thing in common. They, along with many other endangered species, rely on tropical forests for all or part of their habitat.
Orangutans (Pongo pygmaeus) are totally dependent on small and isolated patches of tropical forests remaining in Borneo and Sumatra, Indonesia. Orangutans spend most of their time in the forest canopy where they feed on leaves, figs and other fruit, bark, nuts, and insects. Large trees of the old-growth forests support woody vines that serve as aerial ladders, enabling the animals to move about, build their nests, and forage for food. When the old forests are cut, orangutans disappear.
The largest of all primates, the gorilla, is one of man's closest relatives in the animal kingdom. Too large and clumsy to move about in the forest canopy, the gorilla lives on the forest floor where it forages for a variety of plant materials. Loss of tropical forests in central and west Africa is a major reason for the decreasing numbers of mountain gorillas (Gorilla gorilla). Some habitat has been secured, but the future of this gentle giant is in grave danger as a result of habitat loss and poaching.
The jaguar (Leo onca), a resident of the Southwestern United States and Central and South America, is closely associated with forests. Its endangered status is the result of hunting and habitat loss.
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The Puerto Rican parrot (Amazona vittata), a medium-sized, green bird with blue wing feathers, once inhabited the entire island of Puerto Rico and the neighboring islands of Mona and Culebra. Forest destruction is the principal reason for the decline of this species. Hunting also contributed. Today, only a few Puerto Rican parrots remain in the wild and their survival may depend on the success of a captive breeding program (fig. 9).
In addition to species that reside in tropical forests year round, others depend on such forests for part of the year. Many species of migrant birds journey 1,000 miles or more between their summer breeding grounds in the north and their tropical wintering grounds. These birds are also threatened by tropical forest destruction.
Forestry-loosely defined as the systematic management and use of forests and their natural resources for human benefit-has been practiced for centuries. Most often, forestry efforts have been initiated in response to indiscriminate timber cutting that denuded the land and caused erosion, floods, or a shortage of wood products. Ancient Forestry Practices
In ancient Persia (now Iran), forest protection and nature conservation laws were in effect as early as 1,700 B.C. Two thousand years ago the Chinese practiced what they called "four sides" forestry-trees were planted on house side, village side, road side, and water side. More than 1,000 years ago, Javanese maharajahs brought in teak and began to cultivate it. In the African Tropics, agroforestry (growing of food crops in association with trees) has been practiced for hundreds of years.
In the Yucatan Peninsula of southern Mexico, the ancient Mayas cultivated fruit and nut trees along with such staples as corn, beans, and squash. Bark, fibers, and resin were obtained from plants grown in fields, kitchen gardens, and orchards. Early in their civilization, the Mayas practiced slash-and-burn agriculture. As their population grew, they found more efficient methods of growing crops. They terraced hillsides, learned how to decrease the time between "rotations" of agricultural land with native forests, dug drainage channels and canals to move water to and from cultivated areas, and filled in swampland to plant crops.
The agricultural sophistication of the Mayas enabled their civilization to grow and flourish. What brought about their decline about A.D. 820 is not fully known, but some believe that as their society developed, the Mayas made unsustainable demands on their environment.
Relatively little is known about tropical forestry before the mid1800's in most places. At that time, the European colonial empiresnotably the Dutch, English, and Spanish-brought modern forest management practices to Indonesia, India, Africa, and the Caribbean. Centers for forestry and forestry research were established, and more careful records were kept. Sustainable Forestry
Modern forestry has its basis in 18th-century Germany. Like the Chinese and the Mayan forest practices, German forestry is essentially agricultural. Trees are managed as a crop. Two concepts are important: renewability and sustainability. Renewability means that trees can be replanted and seeded and harvested over and over again on the same tract of land in what are known as crop "rotations." Sustainability means that forest harvest can be sustained over the long term. How far into the future were foresters expected to plan? As long as there were vast acres of virgin (original) forests remaining, this question was somewhat academic. Today, however, sustainability is a vital issue in forestry. Most of the world's virgin forests are gone, and people must rely more and more on second- growth or managed forests. Perhaps we now face, as never before, the limits to long-term productivity.
In the German forest model, forestry is viewed as a continual process of harvest and regeneration. Harvest of wood products is a goal, but a forester's principal tasks are to assure long-term productivity. That is achieved by cutting the older, mature, and slow-growing timber to make way for a new crop of young, fast-growing trees. Harvest-Regeneration Methods
Three examples of timber harvest-regeneration methods (silvicultural systems) illustrate how foresters manage stands to produce timber on a sustained basis. Selection
Individual trees or small groups of trees are harvested as they become mature. Numerous small openings in the forest are created in which saplings or new seedlings can grow. The resulting forest has a continuous forest canopy and trees of all ages. Such systems favor slow-growing species that are shade tolerant. Clearcutting
In clearcutting, an entire stand of trees is removed in one operation. From the forester's point of view, clearcutting is the easiest way to manage a forest-and the most economical. Regeneration may come from sprouts on stumps, from seedlings that survive the logging operation, or from seeds that germinate after the harvest. If natural regeneration is delayed longer than desired, the area is planted or seeded.
Clearcutting systems are often used to manage fast-growing species that require a lot of light. Resulting stands are even aged because all the trees in an area are cut-and regenerated-at the same time. Clearcutting has become controversial in recent years because it has the potential to damage watersheds and because it tends to eliminate species of wildlife dependent on old growth trees. If clearcuts are kept small and the cutting interval is long enough, however, biological diversity may not be impaired. Shelterwood
In shelterwood systems, the forest canopy is removed over a period of years, usually in two cuttings. After the first harvest, natural regeneration begins in the understory. By the time the second harvest is made, enough young trees have grown to assure adequate regeneration. Shelterwood systems favor species that are intermediate in tolerance to shade. Such systems are difficult to use successfully and are the least used of the three silvicultural methods described. Multiple-Use Forestry
Gifford Pinchot, the first Chief of the U.S. Forest Service, was also this country's first professional forester. Pinchot advocated the use of forest resources-all resources, not just timber-for human benefit. Pinchot was a strong and charismatic leader, and his ideas helped shape the course of forestry in the United States.
Pinchot had a vocal opponent in John Muir, a young naturalist from California who believed that public lands should be preserved rather than used. Eventually Muir and Pinchot became rivals for public approval. Oddly enough, there was no
loser in this early conservation battle. Muir's preservation ethic became embodied in the philosophy of the National Parks, and Pinchot's concept of wise use became the guiding principle of the National Forests.
National Forests are still managed under the concepts of multiple use and sustained yield. The dominant uses of National Forests are considered to be wood, water, wildlife, forage (for domestic cattle and wildlife), and recreation. Extraction of minerals and other valuable products is also considered a legitimate use of National Forests. Because Pinchot's philosophy left room for the "highest and best use" of a given area, the U.S. National Forests now include a wilderness system of more than 32 million acres (13 million ha) in which timber harvest is not allowed.
Today it is generally recognized that most, if not all, nondestructive uses of forest are valid. Some areas may be set aside as parks; others for wildlife habitat or as wilderness. Still others will be managed for timber harvest or multiple benefits. Today, conflicts arise primarily over where these different uses will be dominant. In the National Forests, such decisions are made through a land-use planning process in which the public has ample opportunities for input and involvement.
At the turn of the century, very little was known about the world's native forests or how to manage them. In the United States, foresters were quick to recognize the value of information about forests and a branch of research was established in the Forest Service in 1915. Early research was done primarily in support of reforestation efforts, but, as forestry grew in size and complexity, so did the research.
Today, the USDA Forest Service has six regional experiment stations located in important forest regions. Each experiment station has several field laboratories generally with specialized assignments for a geographic region or a specific subject area, and numerous sites for field research. In addition, the Forest Products Laboratory in Madison, WI, serves as a nationwide center for research and development of new technology relating to wood , including tropical woods. Two laboratories are dedicated exclusively to tropical forest research: the International Institute of Tropical Forestry in Puerto Rico and the Institute of Pacific Islands Forestry in Hawaii.
Research is vital for modern forest management, which is information intensive. Today's foresters require vast quantities of data and a knowledge of ecology: they must understand not only the parts of ecosystems but how different parts of the environment interact. Scientific investigations are conducted in support of all kinds of forestry activities: silviculture, forest insect and disease control, wildlife habitat management, fire prevention and control, range and watershed management, forest products utilization, forest survey, reforestation, ecology, and economics.
In the past, timber harvest in the Tropics has seldom been followed by regeneration. Conversion to agriculture is often permanent or results in soil erosion. Timber harvest contracts have usually been short term and have provided little or no incentive for timber companies to replant. So little reforestation has been done in the Tropics that many people believe these forests cannot be restored. However, there are many examples of successful reforestation in India, Indonesia, and the Caribbean.
In the Tropics, as elsewhere, forestry is a mixture of modern innovations and ancient techniques borrowed from local tradition. Plantation forestry is common. Forest reserves have been established for timber harvest, wildlife habitat, scenery, outdoor recreation, or watershed protection. And in the Tropics, agroforestry-tree growing combined with agricultural cropping-is much more common than elsewhere.
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Plantation Forestry
In the Tropics, trees are often planted and grown in plantations for wood production. Often, many species must be tried to determine which will grow best (fig. 10). Plantations must also be supported by major investments in forest management and research. Forest nurseries must be established, and planting techniques and cultural practices (spacing and thinning, pruning, fertilization, insect and disease control, and genetic improvement) must be developed.
Extensive pine plantations have been established in the moist Tropics, mainly in South Africa and Australia. Species most often planted include Caribbean pine (Pinus caribaea), ocote pine (P. oocarpa), slash pine (P. elliottii), and benguet pine (P. kesiya). Pines are popular plantation trees because they are generally fast growing, have good survival rates, and are adapted to a wide variety of environments, including degraded forest sites.
Eucalypts, including species such as Eucalyptus grandis, E. deglupta, E. tereticornis, E. globulus, and E. camaldulensis are favored for the same reasons. Eucalypts are commonly grown for pulp, fuel, and lumber. Other species commonly planted include teak (Tectona grandis), Honduras mahogany (Swietenia macrophylla), melina (Gmelina arborea) beefwood (Casuarina equisetifolia), and Mexican cypress (Cupressus lusitanica). Forest Reserves
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There are many reasons for establishing forest reserves in the Tropics. They can restore watersheds and wildlife habitat, improve scenic beauty and opportunities for outdoor recreation, and produce wood and other products for local use and export. Many forest products contribute to the sustenance and income of local people: wildlife and fish, firewood, rubber, fruits and nuts, rattan, medicinal herbs, floral greenery, and charcoal.
Perhaps the most famous of these reserves is the 5,600 square mile (14,500 k squared) Serengeti National Park in Tanzania. With its vast herds of grazing ungulates (hoofed animals) and predators, including several endangered species, the Serengeti is a showcase of a savanna ecosystem that has long been protected and managed for wildlife and other natural resources (fig. 11). Although plagued with poachers, the Serengeti promotes the cause of wildlife conservation to the many thousands of "ecotourists" who pay to experience nature each year.
Another type of forest reserve is the "extractive" reserve, which is dedicated to the production of useful products. Large reserves of this type have been established recently in Brazil. Local residents use them for tapping rubber, for gathering fruits and nuts, for hunting, and for harvesting wood on a sustained yield basis. Such uses provide a sustainable income while maintaining the ecological integrity of the forest. Agroforestry
The practice growing of trees in combination with agricultural crops is fairly common in the Tropics. It is possible to grow food crops year around in many forested areas, and rural poor depend on this source of food as nowhere else on Earth. Taungya System
Various systems have been developed for combining forestry with agriculture. "Taungya" is a Burmese word meaning cultivated hill plot. This system of agroforestry was developed in Europe during the Middle Ages and probably indepenently in a number of places in the Tropics. After existing forest or ground cover is removed by burning, trees are planted along with agricultural crops. Both are cultivated until the tree canopy closes. Then the area is left to grow trees, and another site is located for combined forestry agriculture. Shade Cropping
An overstory of trees is often used to provide shade for agricultural crops. A common practice is to grow tree species such as guaba Inga vera) over coffee. In Puerto Rico, many forests developed where coffee was once grown in this manner. Support Crops
Trees can be planted to provide support (and sometimes shade) for vine crops. Vines such as pepper and vanilla need support. Alley Cropping
Nitrogen-fixing trees are planted in hedges in widely-space parallel rows along the contour of slopes. Food crops are grown in the "alley" between the rows. The trees add nitrogen and organic matter, protect the soil from erosion, and provide wood and animal forage. Living Fences
Green fenceposts that will root and sprout often are planted in a closely spaced row. When they sprout, they create a "living fence" that provides shade and forage for cattle. Windbreaks
Trees are often planted as windbreaks for agricultural crops, farms, or homesites. Such plantings can eventually contribute wood products as well as shelter. Food trees such as citrus, rubber, and mango can also provide fuel, lumber, and other wood products when they have outlived their original usefulness.
The conservation issues of the past seem simple compared with those of today. As we move toward the 21st century, human societies are concerned with global warming, deforestation, species extinction, and rising expectations. Growing populations must be fed, clothed, and sheltered, and people everywhere want higher standards of living. Global Warming
Warming of the earth's atmosphere is a major environmental issue. Air pollution, deforestation, and widespread burning of coal, oil, and natural gas have increased atmospheric concentrations of carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. These gases trap heat from the sun and prevent it from radiating harmlessly back into space. Thus, the 64 greenhouse" or warming effect is created.
Because of natural variations in climate, it is difficult to measure warming over large areas. Scientists agree, however, that increases in atmospheric concentrations of greenhouse gases will cause higher temperatures worldwide. Even an increase of a few degrees might cause serious melting of the polar icecaps, a gradual rise in sea level, a disruption in normal weather patterns, a possible increase in forest fires, and the extinction of species. Role of Forests
Trees, the largest of all land plants, act as a kind of environmental "buffer" for the ecosystem they dominate. They help ameliorate the extremes of climate (heat, cold, and wind) and create an environment where large land mammals, including people, can live comfortably. Trees complement animals in the global environment. Mammals take in oxygen from the air and exhale carbon dioxide. Plants use the carbon dioxide in their growth processes, store the carbon in woody tissues, and return oxygen to the atmosphere as a waste product. This process, known as photosynthesis, is essential to life. Carbon captured from the atmosphere by photosynthesis is eventually recycled through the environment in a process known as the carbon cycle. Trees have an especially important role in the carbon cycle. Tree leaves also act as filters to remove atmospheric pollutants from the air. This effect is particularly beneficial in urban areas. Forestry Issues
Two key issues will dominate forestry in the years ahead: (1) maintaining long-term productivity of managed forests, and (2) preventing further loss of tropical forests. Both problems will require new approaches to forest management.
Traditionally, forestry has focused on growing crops of wood in plantations or in managed natural stands. In this "agricultural mode," other benefits of forest such as watershed protection, wildlife habitat, climate moderation, and outdoor recreation, have received less attention than wood production.
Perhaps more importantly, the sustainability of the full range of forest benefits has not been measured. There is no question that trees can be grown for crops of wood in managed stands. With intensive management-short rotations, species selection, genetic improvement, fertilization, thinning, and other cultural treatments-more wood can be produced in less time than in natural forests. But for how long? And at what cost in other benefits?
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As more and more of the world's original forests have been cut, the ecological value of forests has come to be more appreciated. In recent years, increased emphasis has been put on what some are calling "ecosystem management." In this model, the health and long-term stability of the forest are paramount, and timber production is considered a byproduct of good forest management rather than the principal product. In Puerto Rico, for example, wood production is a relatively minor aspect of forestry.
Since the 1930's when timber harvests were curtailed, the forests have been managed primarily for watershed protection, wildlife habitat, and outdoor recreation.
There are no easy solutions to the problem of tropical forest destruction, but most experts agree that the problems cannot be solved simply by locking up the forests in reserves. The forests are too important to local people for that to be a workable solution. There is no doubt that tropical forests will be cut. It is better for them to be cut in an ecologically sound manner than to be cleared for poor-quality farmland or wasted by poor harvest practices (fig. 12).
The only real long-term solutions are: (1) more efficient agriculture on suitable farmland, (2) efficient forestry practice including plantations, and (3) reserves to protect species and ecosystems. Many forestry experts believe that we have only begun to tap the potential for wise use of tropical forests. Many uses have yet to be fully explored. We are only starting to learn the value of tropical forests for medicines, house and garden plants, food and fiber, tourism, and natural resource education.
Jeremy Here is a site that answers Question "a","c", and touch a little on "b"and "d" ...
[[http://saferenvironment.wordpress.com/2008/08/20/rainforest-conservation-%E2%80%93-challenges-of-addressing-deforestation-issues/|]]http://saferenvironment.wordpress.com/2008/08/20/rainforest-conservation-%E2%80%93-challenges-of-addressing-deforestation-issues/ and here is some content... The rainforest biome (a major habitat type) can be defined as forest growing in regions with more than 200 cm (6.5 feet) of rainfall per year. Although there are temperate rainforests (such as that of British Columbia in Canada), tropical rainforests occur between the Tropic of Cancer and the Tropic of Capricorn (23.5o N and 23.5o S). They are found in regions where the average temperatures of the three warmest and the three coldest months do not differ by more than 5o C, although there may be daily variations of more than that. Rainfall is relatively evenly distributed, which allows the growth of a heavy canopy of broad-leaved evergreen tree. The rainforests are home to more than half the animals in the world. Rainforest animals reside in all four strata of the forest. ‘Strata’ means ‘layers’. Scientists divide rainforests into different strata (or layers) for easy reference. Each of these layers is a very different environment and supports different life forms. The strata differ in many ways, including temperature, the amount of sunlight that they receive, the wetness of the environment and the amount and types of life forms living in it. Today tropical rainforests are disappearing from the face of the globe more rapidly than anything else. As per the estimation, despite growing international concern, rainforests continue to be destroyed at a pace exceeding 80,000 acres (32,000 hectares) per day. World rainforest cover now stands at around 2.5 million square miles (6 million square kilometers), representing around 5 percent of the world’s land surface. Unfortunately, much of this remaining area has been impacted by human activities and no longer retains its full original biodiversity. Deforestation of tropical rainforests has a global impact through species extinction, the loss of important ecosystem services and renewable resources, and the reduction of carbon sinks. The problem must be remedied, but the means are not as simple as fortifying fences around the remaining rainforests or banning the timber trade. Economic, political, and social pressures are not allowing rainforests to persist. Forces behind rainforest loss – Countries with significant rainforest cover are generally among the world’s poorest. Therefore, rainforests are being cut mostly for economic reasons, though there are political and social motivations as well. A significant portion of deforestation is caused by poor farmers simply trying to eke out a living on marginal lands. Beyond conversion for subsistence agriculture, activities like logging, clearing for cattle pasture and commercial agriculture are sizeable contributors to deforestation on a global scale. Agricultural fires typically used for land-clearing are increasingly spreading outside cultivated areas and into degraded rainforest regions. Addressing deforestation issues - Addressing deforestation is a quite tougher job. Different needs and interests of various groups of people have to be taken into consideration while addressing the deforestation matter. a. Rural farmers – Poor farmers are simply trying to put food on the table for their families. A better approach to addressing the needs of the rural poor may be improving and intensifying currently existing agricultural projects and promoting alternative cultivation techniques. b. Industrial/commercial developers – At present, illegal logging and counterfeit labeling are major obstacles facing sustainable forest management for timber, but in time the development of higher yielding timber plantations will help alleviate pressures on natural forests. Increased raw material need of the emerging economies is again main reason of large scale deforestation, which need to be curtailed by promoting culture of recycling almost every product we use and by conservation. c. Restoring and rehabilitating ecosystems – There is no use bemoaning past deforestation of large areas. Today the concern is how to best utilize lands already cleared so that, they support productive activities, now and for future generations. Without improving the well-being of people living in and around forests, we cannot expect rainforests to persist as fully functional systems and continue to cater to our needs. To lessen future forest loss, we must increase and sustain the productivity of farms, pastures, plantations, and scrub land in addition to restoring species and ecosystems to degraded habitats. By reducing wasteful land-use practices, consolidating gains on existing cleared lands, and improving already developed lands, we can diminish the need to clear additional forest. d. Funding rainforest conservation efforts – Conservation efforts and sustainable development programs are not going to be cost-free. Even countries that already get considerable aid from foreign donors have trouble effectively making such initiatives work in the long term. Some of the following funding strategies may be considered: (i) Ecotourism —Ecotourism can fund efforts both through park entrance fees and employing locals as guides and in the handicraft and service sectors etc. (ii) Bio-prospecting fees —Rainforest countries can earn revenue by allowing scientists to develop products from the country’s native plant (e.g., with potential pharmaceutical applications etc.) and animal species. The royalties obtained from such commercial agreement should be set aside for conservation projects developed through local communities. (iii) Carbon credits – For setting aside forest for the purpose of atmospheric carbon mitigation, developing countries can receive payments from industrialized countries looking to offset their carbon emissions. (iv) Corporate sponsorship – Corporations have the money and a marketing-driven interest in taking a closer look at sponsorship issue. e. Further steps to be taken once funding is in place – Further steps are to be taken in order to reduce deforestation activities, these are : (i) Expand protected areas—As many areas should be protected as soon as possible. If protected areas can be developed in such a manner to generate income for local communities, an increasing number of parks should theoretically create more economic benefits for a greater share of the population. (ii) Increase surveillance of and patrols in protected areas—This can be done at a reduced cost if local communities benefit from the success of the park. If locals have a vested interest, i.e. are compensated via entrance fees etc.; they will want to watch the park so that the source of their income is not diminished. Community surveillance is the most effective way to patrol a protected area, though it will probably be necessary to have park staff conduct patrols as well. Guides should be trained as well to keep watch for activities that are damaging to the ecosystem and report suspicious activities at park headquarters. (iii) Build research facilities for training local scientists and guides. (iv) Establish programs that promote sustainable use. (v) Compensate displaced people. (vi) Promote ecotourism. (vii) Ensure economic success does not result in increased deforestation. (viii) Encourage entrepreneurship – Encouraging entrepreneurship through such a micro-credit strategy could pay significant dividends for a country’s economy as a whole. Conclusion – Simply banning the timber trade or establishing reserves will not be enough to salvage the world’s remaining tropical rainforests. In order for the forest to be preserved, the underlying social, economic, and political reasons for deforestation must be recognized and addressed and here is a diagram.
here is the info. It answers "d" and a little of "e"
Rainforests around the world still continue to fall. Does it really make a difference? Why should anyone care if some plants, animals, mushrooms, and microorganisms perish? Rainforests are often hot and humid, difficult to reach, insect-ridden, and have elusive wildlife.
Actually the concern should not be about losing a few plants and animals; mankind stands to lose much more. By destroying the tropical forests, we risk our own quality of life, gamble with the stability of climate and local weather, threaten the existence of other species, and undermine the valuable services provided by biological diversity.
While in most areas environmental degradation has yet to reach a crisis level where entire systems are collapsing, it is important to examine some of the effects of existing environmental impoverishment and to forecast some of the potential repercussions of forest loss. Continuing loss of natural systems could make human activities increasingly vulnerable to ecological surprises in the future.
The most immediate impact of deforestation occurs at the local level with the loss of ecological services provided by tropical rainforests and related ecosystems. Such habitats afford humans valuable services such as erosion prevention, flood control, water treatment, fisheries protection, and pollination—functions that are particularly important to the world's poorest people, who rely on natural resources for their everyday survival. Forest loss also reduces the availability of renewable resources like timber, medicinal plants, nuts and fruit, and game.
Over the longer term, deforestation of tropical rainforests can have a broader impact, affecting global climate and biodiversity. These changes are more difficult to observe and forecast from local effects, since they take place over a longer time scale and can be difficult to measure
^ Moran]], E.F., "Deforestation and Land Use in the Brazilian Amazon", Human Ecology, Vol 21, No. 1, 1993
“It took more than 15 years for the "lungs of the world" myth to be corrected. Rainforests contribute little net oxygen additions to the atmosphere through photosynthesis.”
^ Philip L. Walker, Larry Sugiyama, Richard Chacon. (1998) '"Diet, Dental Health, and Cultural Change among Recently Contacted South American Indian Hunter-Horticulturalists" in ''Human Dental Development, Morphology, and Pathology''. University of Oregon Anthropological Papers, No . 54
^ Philip L. Walker, Larry Sugiyama, Richard Chacon. (1998) '"Diet, Dental Health, and Cultural Change among Recently Contacted South American Indian Hunter-Horticulturalists" in ''Human Dental Development, Morphology, and Pathology''. University of Oregon Anthropological Papers, No . 54
^ Philip L. Walker, Larry Sugiyama, Richard Chacon. (1998) '"Diet, Dental Health, and Cultural Change among Recently Contacted South American Indian Hunter-Horticulturalists" in ''Human Dental Development, Morphology, and Pathology''. University of Oregon Anthropological Papers, No . 54
^ Myers, N. 1985. The primary source W. W. Norton and Co., New York, pp. 189-193.
In addition to extractive human uses rain forests also have non-extractive uses that are frequently summarized as ecosystem services. Rain forests play an important role in maintaining biological diversity, modulating precipitation, infiltration and flooding, increasing scientific knowledge and in the spiritual well-being of humans. Such ecosystem services are of use to humans without the need for any modification or management of the forest yourself.
Academic resources
''Agricultural and Forest Meteorology'' <ref name=afm>cite web
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| title = Agricultural and Forest Meteorology
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| url = http://www.sciencedirect.com/science/journal/01681923
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What is the real value of tropical forests? By now, you may have heard a lot about the two most important and commonly recognized services that tropical rain forests provide to the humanity:
Amazon Tropical Forest, Brazil
- They regulate global climate patterns and help mitigate negative effects of climate change, specifically, global climate warming, (Service 1), and
- They serve as storages of global biodiversity, specifically plant and animal diversity (Service 2).
Those are the two main factors that have been widely put forward as the arguments which are strong enough for us people to try to do our utmost to “save the rain forests” from their continuous destruction.Rain Forest Service 1 – Regulating Climate Patterns
There is a strong interdependent relationship between the climate and the tropical rain forests.On the one hand , favourable local climatic conditions determine the existence of rain forests in principle in a certain location. (2)
For example, true tropical rain forests can only exist in geographical locations with “continuous supply” of rainfall and sunshine. Such locations are mostly found in the geographical areas around the equator.
On the other hand , rain forests affect the global climatic conditions by acting as pollution filters / “carbon sinks” / “lungs of the earth”.
Rain forest trees absorb carbon dioxide (CO2) and produce oxygen back into the atmosphere, by way of photosynthesis. (3)
In very simple terms, such carbon absorption by rain forests helps reduce the amount of CO2 that could otherwise be released into the Earth’s atmosphere and cause global warming . (4)
Rain Forest Service 2 – Biodiversity
Biodiversity (biological diversity) is defined as a number and variety of plant and animal species in a certain habitat.We know that tropical rain forests have the highest levels of biodiversity, as compared to any other place in the world.
For example, from one of the UN Chronicle issues we learn that a 2,500-acre area of a typical tropical rain forest is home to some 1,500 species of flowering plants, 750 species of trees, 400 species of birds and 150 different species of butterflies. (5)
In another example, check out some facts about the Ecuador rainforest , one of the most biodiverse places on the planet.
Endangered Orangutans
Rain forests are home to a large number of endangered animals , such as the mountain gorilla , which are crucial components of tropical biodiversity.
But why is it so important for us to preserve biodiversity as much as we only can?
From the utilitarian point of view, the common answer to that question is:
If we continue to lose biodiversity, we are going to lose out on potential discoveries of new foodstuffs, medicines, industrial raw materials.
This is not to mention the fact that it would be nice for the human race to allow other life forms, that comprise biodiversity as such, to live peacefully, just because they already exist.
More on Rainforest Services
It goes without saying that the two services we’ve described above are of crucial importance.But let’s take a closer look at the uses of tropical rain forests.
A. Rain Forests As Habitats
For thousands of years, rain forests had been home for all the life forms residing in them, including animals and humans (forest (indigenous) people).
Toucans call rainforest home
Animals had been utilizing their natural habitats as their needs guided them (by “taking” whatever they needed from their environment (such as food) and “giving back” in some other way (for example, by becoming “food” for some larger predators).
Forest people, on their part, had been historically using rain forest resources in very sustainable ways (6) – the knowledge they had been gathering over centuries from their ancestors and transferring to their offspring.
In most recent times (the last several decades) rain forests have also become home to many new peasant settlers / migrants who moved to their new habitats as a result of their governments’ resettlement programmes, in search of new land for agricultural purposes. (7)
B. Rain Forests As Resource Bases
Following on from the discussion of biodiversity above, it is no surprise that the tropical rain forests are sometimes referred to as an "inexhaustible treasure trove" of nature . (8)
We can distinguish three major groups of goods that come from the rain forests:
- food
- medicines / drugs
- commercial / industrial goods
Since the middle ages, tropical rain forests attracted the attention of many European travellers.The large-scale exploitation of rain forest resources must have started as one of by-products of the industrial revolution in Europe in the 18 th – 19 th centuries.
Rubber was one of the rain forest’s most prominent products, which indeed found many uses in newly born industrial societies. And perhaps, one of its most famous applications was for rubber tyres which were originally used in bicycles, and consequently in motor cars. (9)
As for the foodstuffs, you wouldn’t believe how much food that we consume every day originated from the rain forests.
Coffee Bean Harvester
Vanilla and cacao beans (used to make chocolate), for example, were discovered during the very early voyages of the conquistadors to the Americas. (10)
It is hard to overestimate the importance of rain forest food products in modern times.
Chris Park mentions that about 12 crops provide 90% of the world’s food and half of them come from tropical rain forests including rice and maize . (11)
Even the domestic chicken was apparently bred from the red jungle fowl of Indian forests. (12)
Products like coffee , bananas , tea , sugar , pineapples , avocados and a lot more are widely used both for local consumption in the rain forest home countries and for exports.
Currently, a vast number of rain forest plants are also widely used in medicines. (13)
The “most lucrative” rain forest resources
There is virtually no doubt that, historically, logging had been the most lucrative business activity in the tropical rain forests.
This activity allows an accumulation of short-term profits without substantial long-term investments from logging companies.
In the most recent years, relative political and economic stability of rain forest countries allowed for the development of other extractive industries, such as mining and oil & gas . (14)
All these activities have inevitably caused, and are still causing, serious environmental damage.
Specifically, this leads to deforestation of pristine ancient rain forest ecosystems and an irreversible loss of valuable forest biodiversity.
C. Rain Forests As Unique Guarantors Of Local Environmental / Climatic Stability (15)
Apart from helping to regulate the global climatic conditions, rain forests also guarantee local environmental stability in several ways.
What happens if rain forests are removed?
1. Soil Erosion
Barren Soil
Rain forest soils are quite poor in nutrients, as virtually all of them are contained within the forest vegetation and animal biomass (thanks to the very efficient nutrient cycling within the forests).
So if a forest is cleared, the soil is fully exposed to heavy rainfalls that can easily wash away the topsoil and degrade the soil quality.
Once the topsoil is away, it leaves the deeper soil layers exposed to the air. The air hardens the deeper soil and degrades it even further.
Thus, such degraded soil can hardly be used for any productive activity.
2. Downstream silting
As the rainfalls wash away the rain forest soil, they can push such sediments to rivers, water reservoirs and irrigation systems and leave them silted.
This can cause contamination of drinkable water as well as interruption of operations of hydroelectric installations.
Higher river silt levels can also expose river-neighbouring areas to floods.
3. Downstream flooding
As a result of deforestation a larger proportion of rainfall, that would have otherwise been absorbed by the vegetation, is now directly transferred into river systems and may cause serious flooding in river-neighbouring areas.
4. Droughts
Rain forest vegetation stores a lot of moisture that evaporates and comes back as rainfall.
If this natural storage of moisture is destroyed, less rainfall is recycled and droughts ensue.
As an example, experts blame such rain forest clearance for recent droughts in Australia. (16)
5. Rain Forests Help Reduce the Amount of Solar Radiation Reflected Back Into the Atmosphere
Rainforests absorb large amounts of solar radiation
When solar radiation reaches the surface of the Earth, some of this radiation is absorbed by the planet and some of it is reflected back into space.
Some of this radiation reflected back will actually escape into space, and some of it will get trapped in the atmosphere.
A certain proportion of the radiation trapped in the atmosphere will then be re-reflected down to the planet and thus force the temperature to rise.
This is called a greenhouse effect , and it causes global warming.
So the importance of the rain forest vegetation from this point of view is that it helps reduce the amount of solar radiation reflected back into the atmosphere and therefore helps keep the temperatures stable.
Tropical Rain Forest Destruction - One of The Biggest Problems of Modern Times
Having considered all the services that tropical rainforests provide, it is really hard to overestimate their overall value to all of us inhabiting planet Earth.Yet, all too often, financial gains take precedence over the urgent need for rain forest conservation.
Egbert Leigh Jr. refers to the tropical forest as “a victim of a spiritual crisis in humanity”. (17)
As an excellent illustrative example, find out how the Panama Canal construction almost a century ago affected this country's ecological situation by flooding many kilometers of its rainforests.
How very true this statement is!
Rain forest destruction is a very serious issue.
Virtually all the rain forest countries are developing countries and they are tempted to use their tropical resources for their economic and social development.
The fact that many of these countries have crippling amounts of foreign debt complicates the situation even further as these governments quite often resort to the use of precious forest reserves to repay their lenders.
Global warming may damage the rainforests
See here for a more detailed discussion of rain forest destruction .
But it is not only the structural destruction of rain forests that is a problem we have to deal with.
It is also on-going environmental pollution that seriously affects the health of these vulnerable ecosystems.
We discuss the problem of pollution and its impacts on the rain forests here.
To crown it all, the healthy functioning of rain forests may also be severely disrupted by global warming .
Prospects for the Future?
Not everything is doom and gloom though.For example, the deforestation rate of the Amazon rain forest (the largest tropical fain forest in the world) during 2005–2006 was the lowest since 1991. (18)
People in many different countries of the world now recognise the real dangers of global warming and are actually expressing the willingness to pay higher bills to reverse this process. (19)
Year 2007 also saw the world’s special recognition of the climate change problem, as the Nobel Peace Prize for this year went to the United Nations’ Intergovernmental Panel on Climate Change (UN IPCC) and Al Gore Jr.: “for their efforts to build up and disseminate greater knowledge about man-made climate change”. (20)
So we should all put as much effort as possible to prevent further destruction of tropical rain forests and save our planet from a potential ecological disaster – we don’t have a choice!
http://www.tropical-rainforest-animals.com/Tropical-Rain-Forests.html
Lim Wei Liang: As you realize that global warming IS REAL, opportunities and need both increase for rainforest conservation. Info has been out there for decades, but maybe the public eye has become so accustomed to the burning and clear-cutting pictures, it no longer really notices them.Logging - much of it done illegally - is the most visible form of rainforest destruction.
Clear-cutting is usually the most profitable means of harvesting valuable timber, because the rainforest tends to be an "equal opportunity grower" with trees of high monetary value interspersed with what are seen as "junk" trees.
At least with logging, not everything is wasted, as happens when the forest is burned to clear it for pasture or other agriculture. Burning rainforests can be clearly seen from outer space , as this astronaut's photo of Mexico shows - what looks like white dots are actually fires.
But even with careful deforestation - selective logging - the roads that are built for logging access wind up being used for human activities that are further damaging to delicate ecosystems.
Why You Should Share Rainforest Conservation Info
Rainforests are crucial to the ecosystem of our planet. They have been described as the Earth's "lungs" or respiratory system. The massive numbers of trees and other plants absorb carbon dioxide (CO2), and then "breathe out" oxygen, which we need to survive.We (humans and animals) breathe in the air around us, take in the oxygen, then throw off carbon dioxide as we exhale. This is a great arrangement, because everything balances out, if all is working as it should.
Unfortunately, the use of fossil fuels (carbon that has been stored underground for millennia, and is now being released) is dramatically increasing the world-wide levels of CO2. So just at the time we need all those trees in the rainforest the very most , we are destroying them through ignorance and greed.
Rainforests are also home to loads of wildlife and plant species, many of which have never even been documented. Many scientists believe the potential is huge for finding medical cures in these tropical regions.
As we destroy the forests, we also wipe out the indigenous cultures and people who have lived there for generations.
Find extensive rainforest conservation info at Mongabay.com
What Can You Do to Help Preserve the Rainforests?
It's true that this a huge and terrible mess, but, short of going into the Amazon jungle and chaining yourself to a tree (not a really useful activity), there are many little things you can do to help save the rainforests.
Anything you accomplish that will prevent Global Warming will also help with rainforest conservation (info here) .
You can buy a tree, or purchase the timber rights on an acre of rainforest.
And of course there are many great non-profit organizations who urgently need your contributions. You can even trigger a donation to save the rainforest by simply clicking the mouse on your computer.
http://www.greenhq.net/rainforest-conservation-info.html
Rainforests of the World
Wild and wondrous, rainforests extend from as far as Alaska and Canada to Latin America, Asia and Africa. They nurture thousands of plants and animals found nowhere else on Earth and provide life's essentials such as our medicines, food and water.The Nature Conservancy is working around the world in places like Costa Rica's Osa Peninsula to protect rainforests, engaging local and indigenous communities in creative solutions that balance the needs of people with nature.
Why Should You Care About the Rainforest?
Besides providing food, water and air to the rest of the world, rainforests offer critical habitat for many of the Earth's most interesting and rare plants and animals. Read on for more [[rainforests/explore/facts.html|rainforest facts]]:The Nature Conservancy's Rainforests Work
The Nature Conservancy has launched many conservation programs to protect these vital forests and all the plants, animals and people that depend on them. Working in many of the world's most threatened forest systems, The Nature Conservancy has had many tangible and lasting successes:- Plant and animal diversity assessments of the coastal Amazon rainforest;
- Training for national park guards in Bolivia;
- Support for implementing rainforest protection projects in the Asia Pacific region;
- Sustainable income-generating projects in Chile;
- Effective park management in Panama and Costa Rica;
- Scientific analysis of new protected areas within temperate rainforests in Canada; and
- Since its beginning, our Adopt an Acre® program has protected hundreds of thousands of forested acres worldwide.
As some of the last truly wild places left in the world, rainforests deserve our immediate attention. You can help preserve the world's rainforests and the local communities around them when you adopt an acre of rainforest today .How Can You Help Save the Rainforest?
We are all part of this Earth. Invest in our future and the future of our planet. Be a steward of the rainforests.When you make a gift to protect the rainforest , you'll help to ensure that the world’s most vital forests like the Osa are restored, protected and sustained for future generations.
http://www.nature.org/rainforests/
Wei Liang: Here is another URL, from that website you can probably find out a lot of stuff and there are many links from that website too.
?http://rainforests.mongabay.com/0101.htm
http://www.ias.ac.in/currsci/jul252008/216.pdf
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 216 95, NO. 2, 25 JULY 2008
*For correspondence. (e-mail: ravi@ces.iisc.ernet.in)
Forest conservation, afforestation and
reforestation in India: Implications for
forest carbon stocks
N. H. Ravindranath1,*, Rajiv Kumar Chaturvedi2 and Indu K. Murthy2
1Centre for Sustainable Technologies, and 2Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India
This article presents an assessment of the implications
of past and current forest conservation and regeneration
policies and programmes for forest carbon sink in
India. The area under forests, including part of the
area afforested, is increasing and currently 67.83 mha
of area is under forest cover. Assuming that the current
trend continues, the area under forest cover is
projected to reach 72 mha by 2030. Estimates of carbon
stock in Indian forests in both soil and vegetation
range from 8.58 to 9.57 GtC. The carbon stock in existing
forests is projected to be nearly stable over the
next 25 year period at 8.79 GtC. However, if the current
rate of afforestation and reforestation is assumed
to continue, the carbon stock could increase from
8.79 GtC in 2006 to 9.75 GtC by 2030 – an increase of
11%. The estimates made in this study assume that
the current trend will continue and do not include
forest degradation and loss of carbon stocks due to
biomass extraction, fire, grazing and other disturbances.
Keywords: Afforestation, carbon stocks, conservation,
reforestation.
INDIA is a large developing country known for its diverse
forest ecosystems and is also a mega-biodiversity country.
Forest ecosystems in India are critical for biodiversity,
watershed protection, and livelihoods of indigenous and
rural communities. The National Communication of the
Government of India to the UNFCCC has reported1 that
the forest sector is a marginal source of CO2 emissions.
India has formulated and implemented a number of policies
and programmes aimed at forest and biodiversity
conservation, afforestation and reforestation. Further, India
has a goal2 to bring one-third of the geographic area under
forest and tree cover by 2012. All forest policies and
programmes have implications for carbon sink and forest
management. This article presents an assessment of the
implications of past and current forest conservation and
regeneration policies and programmes for forest carbon
sink in India. It also estimates the carbon stocks under
current trend scenario for the existing forests as well as
new area brought under afforestation and reforestation for
the period 2006–30.
We have primarily relied on published data from the
Ministry of Environment and Forests (MOEF), Government
of India (GOI); Food and Agricultural Organization
of United Nations (FAO), and Forest Survey of India
(FSI). We have used the Comprehensive Mitigation Analysis
Process (COMAP) model for projecting carbon stock
estimates. The article is based only on past trends from
1980 to 2005 and uses the assumption – ‘if the current trend
continues’. We feel that such an assumption is well justified
because, despite the increase in population and industrialization
during 1980–2005, forest area in India not
only remained stable but has marginally increased. This
is due to favourable policies and initiatives pursued by
GOI. We expect that India will not only keep pursuing
aggressive policies of afforestation and forest conservation,
but also go a step forward. A case in point is the
Prime Minister’s recently announced ‘6 mha greening
programme’. If the assumptions of continuation of current
rates of afforestation, forest conservation policies
and no significant degradation of forest carbon stocks are
changed, the future carbon stocks projected will also
change.
Area under forests
According to FSI, ‘all lands, more than one hectare in
area, with a tree canopy density of more than 10 per cent
are defined as Forest’. The total forest cover in India according
to the latest3 State of Forest Report 2003 is
67.83 mha and this constitutes 20.64% of the geographic
area. The distribution of area under very dense, dense and
open forest is given in Table 1. Dense forest dominates,
accounting for about half of the total forest cover. Tree
cover (which includes forests of less than 1 ha) is 9.99 mha
(3.04%). The total area under forest and tree cover is
77.82 mha, which is 23.68% of the geographic area (Table 1).
FAO4 defines forests as ‘Land spanning more than 0.5 ha
with trees higher than 5 m and a canopy cover of more
than 10%, or trees able to reach these thresholds in situ’.
And other woodlands as ‘Land not classified as “Forest”,
spanning more than 0.5 ha; with trees higher than 5 m
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 217
and a canopy cover of 5–10 per cent, or trees able to
reach these thresholds in situ; or with a combined cover
of shrubs, bushes and trees above 10 per cent. Both of
these categories do not include the land that is predominantly
under agricultural or urban land use’. According to
FAO, the area under forests and other wooded land in
India has increased from 63.93 mha in 1990 to 67.70 mha
in 2005. Thus FAO estimates do not significantly differ
from FSI estimates.
Trends in area under forest and tree cover
The FSI has been periodically estimating the forest cover
in India since 1987, using remote sensing techniques. The
forest cover reported5 for 1987 was 64.08 mha and according
to the latest assessment3 for 2003, the forest
cover is 67.83 mha. This indicates an increase in forest
cover of 3.75 mha over a period of 15 years (Figure 1). It
can be observed from Figure 1 that the forest cover in India
has nearly stabilized and has been increasing marginally
over the years3,5–12. FSI has included the tree cover in
the 2001 and 2003 assessments3,6, in addition to forest
cover. The area under tree cover reported is also found to
be marginally increasing (Figure 1).
Afforestation and reforestation programmes
India has been implementing an aggressive afforestation
programme. The country initiated large-scale afforestation
under the social forestry programme starting in the
Table 1. Status of forest cover in India3,4
Per cent
Tree crown class Area (mha) geographic area
Very dense forest (>70%) 5.13 1.56
Dense forest (40–70%) 33.93 10.32
Open forest (10–40%) 28.78 8.76
Mangroves 0.45 0.14
Total forest cover 67.83 20.64
Tree cover 9.99 3.04
Total 77.82 23.68
Forest cover according to FAO 67.7 –
0
10
20
30
40
50
60
70
80
90
1987 1989 1991 1993 1995 1997 1999 2001 2003
Forest and tree cover (Mha)
Forest cover Tree cover
Figure 1. Trends in area under forest and tree cover3,5–12.
early 1980s. Figure 2 shows the progress of afforestation
in India for the period 1951–2005. It can be seen from
Figure 2 that the cumulative area afforested in India during
the period 1980–2005 is about 34 mha, at an average
annual rate2 of 1.32 mha2. This includes community woodlots,
farm forestry, avenue plantations and agro-forestry.
Afforestation and reforestation in India are being carried
out under various programmes, namely social forestry
initiated in the early 1980s, Joint Forest Management
Programme initiated in 1990, afforestation under National
Afforestation and Eco-development Board (NAEB) programmes
since 1992, and private farmer and industryinitiated
plantation forestry.
Future trends in area under forests and
afforestation
The projections for area under forest as well as area afforested
are based on current trends or what is generally
termed the ‘current trend scenario’. The current trend scenario
is based on the past, current and short-term afforestation
plans. The projections exclude the tree cover
component as reported in 2001 and 2003 by the FSI.
Projections for area under forest cover based on
current trend scenario
The forest cover is projected up to 2030, based on the
past and current trends, as reported by the periodic re-
Figure 2. Cumulative area afforested2 during 1951–2005.
Projected trend in forest cover under the current trend scenario3,5–
.
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 218 95, NO. 2, 25 JULY 2008
ports of the FSI. It can be observed from Figure 3 that the
forest cover will continue to increase all the way up to
2030. The forest cover is projected to reach 72.19 mha by
2030, assuming that the current trend scenario will continue.
Projected afforestation rates based on current
trends
The long-term average annual rate of afforestation over
the period 1980–2005 is 1.32 mha. Assuming the average
rate2 of 1.32 mha for the period 2006–30, the total area
that would be afforested is 33 mha. The cumulative area
afforested would be 70.5 mha by 2030 (Figure 4). This
includes short- and long-rotation plantation forestry as
well as natural regeneration. It is important to note that
some of the afforested area, particularly short-rotation
plantations, is likely to be periodically harvested and replanted
or left for coppice regrowth.
Carbon stocks in forests
The forest sector could be a source or a sink of carbon.
Forest carbon stock includes biomass and soil carbon
pools. Biomass carbon can be further disaggregated into
aboveground and belowground biomass and dead organic
matter. Change in forest carbon stock between two time
periods is an indicator of the net emissions of CO2 from
the sector. Carbon stocks are estimated and projected for
the period 2005–30.
Methodology
The COMAP model13 is a set of versatile models with the
ability to analyse the mitigation potential as well as costeffectiveness
of diverse activities such as forest conservation
(e.g. Protected Areas and halting forest conversion),
Figure 4. Projected afforestation under the current trend scenario.
natural regeneration (with no logging) and afforestation/
reforestation through plantation forestry, including
short- as well as long-rotation forestry (with logging or harvesting).
Assessment of mitigation activities using the COMAP
model would involve consideration of the following:
• Land availability for different mitigation activities
during different years.
• Wood product demand and supply to ensure that socioeconomic
demands are met with and real additional
mitigation is feasible.
• Developing a baseline or current trend scenario to enable
estimation of incremental carbon mitigation.
• Developing a mitigation scenario incorporating the
extent of area to be covered for meeting different
goals.
Data required for assessing different activities: The data
required for assessing the mitigation potential of afforestation
and reforestation include land area-related information,
baseline carbon density (tC/ha) in above-ground
vegetation and soil, rotation period, above-ground woody
biomass accumulation rate (tC/ha/yr), soil carbon enhancement
rate (tC/ha/yr), and cost and benefit flows. Input
data were obtained from the literature14,15.
Outputs of the COMAP model: These include mitigation
potential estimates per ha and aggregate tonnes of
carbon benefit, annual carbon stocks, carbon stocks for a
given year such as 2008 and 2012 and cumulative over a
period, and cost-effectiveness parameters.
Carbon stock estimates
Estimates for the forest carbon stocks, including biomass
and soil carbon from previous studies are given in Figure
5. According to an earlier estimate by Richards and Flint16,
0
2000
4000
6000
8000
10000
12000
1880
1980
1986
1986
1994
2005
Carbon stock (MtC)
Biomass carbon Soil carbon
Figure 5. Trends in carbon stock estimates for Indian forests15–19.
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 219
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030
Carbon stock (MtC)
Forest Short rotation Long rotation Natural regeneration
0
2000
4000
6000
8000
10000
12000
2006 2008 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030
Carbon stock (MtC)
Soil carbon Biomass carbon
Figure 6. Projected forest carbon stocks. a, Under the current trend scenario for existing forests and area afforested (short- and
long-rotation and natural regeneration). b, According to biomass and soil carbon.
the biomass carbon stock in Indian forests was 7.94 MtC
during 1880. This study does not provide soil carbon estimates.
Further estimates by the same authors for 1980
showed that forest biomass carbon stock had declined by
nearly half over a period of 100 years. Estimates17–19 of
forest carbon stock, including biomass and soil carbon for
the year 1986, are in the range 8.58–9.57 GtC. According
to a latest estimate by FAO4, total forest carbon stock in
India is 10.01 GtC. Thus, the carbon stocks in Indian forests
have not declined, and in fact seem to have increased,
over a period of 20 years (1986–2005). Forest soil carbon
accounts for over 50% of the total forest carbon stock.
Carbon stock projections under current trend
scenario
Carbon stock projections for the existing forests as well
as new area brought under afforestation and reforestation
for the current trend scenario are made for the period
2006–30. The carbon stock projections are made using
the COMAP model. The forest cover data were obtained
from the projections made using the FSI area trends (Figure
3) and afforestation rates were obtained from the past
trends (average annual rate of 1.32 mha). The biomass
and soil carbon stock and growth rates were obtained from
published literature14,15. The afforestation rate of 1.32 mha/
annum was allocated to short- and long-rotation and natural
regeneration at 63.7, 32.2 and 4.1% respectively,
based on the previous years’ trend12.
The carbon stock projections for the period 2006–30
are given in Figure 6. The carbon stock in the existing forests
is projected to be nearly stable over the 25-year period
at 8.79 GtC (Figure 6 a). When afforestation and
reforestation is included, the carbon stock is projected to
increase from 8.79 GtC in 2006 to 9.75 GtC by 2030,
about 11% increase (Figure 6 a). It is important to note
that COMAP model accounts for harvests and the resulting
emissions. Thus, Indian forests will be a net sink over
the next 25 years. Figure 6 b shows the dominance of soil
carbon in the total forest carbon stock.
Factors contributing to stabilization of carbon
stocks in Indian forests
India is one of the few countries where deforestation rate
has been reduced and regulated and forest cover nearly
stabilized, unlike most other tropical countries. Further,
the projections of carbon stocks for the period 2006–30
showed that the carbon stock will increase. Thus, it is
important to understand the likely factors contributing to
the observed and projected stabilization of forest cover as
well as forest carbon stocks in India. The factors include
legislations, forest conservation and afforestation programmes,
and community awareness and participation.
Forest Conservation Act, 1980
This Act is one of the most effective legislations contributing
to reduction in deforestation. This was enacted to
reduce indiscriminate diversion of forest land for nonforestry
purposes, and to help regulate and control the recorded
forest land-use changes.
Compensatory afforestation
According to Forest Conservation Act, 1980, when after
careful consideration forest land is released for any infrastructure
projects, it is mandatory for compensatory plantations
to be raised on an equivalent non-forested land or
equal to double the area on degraded forestland.
Wildlife parks and protected area
In India, 15.6 mha is Protected Area, where all human intervention
or extraction is banned.
Afforestation
India has been implementing large-scale afforestation/
reforestation since 1980 under social forestry, Joint Forest
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 220 95, NO. 2, 25 JULY 2008
Management, silvi-pasture, farm forestry and agro-forestry
programmes, covering over 30 mha. This may have reduced
pressure on the forests.
National Forest Policy, 1988
It envisages people’s participation in the development and
protection of forests. The basic objective of this policy is
to maintain environmental stability through preservation
of forests as a natural heritage.
Joint Forest Management (JFM), 1990
The Forest Policy 1988 set the stage for participatory forest
management in India. The JFM programme recognized
the rights of the protecting communities over forest lands.
The local communities and the Forest Department jointly
plan and implement forest regeneration programmes and
the communities are rewarded for their efforts in protection
and management. The total area covered under the JFM
programme is over 15 mha. This has enabled protection
of existing forests, regeneration of degraded forests and
raising of forest plantations, potentially contributing to
conservation of existing forests and carbon stocks.
Significance of stabilization of forest carbon
stocks in India
India is one of the few countries in the world, particularly
among the tropical countries, where carbon stock in forests
has stabilized or is projected to increase. This has implications
for reducing the carbon emissions from forest sector,
potentially contributing to stabilization of CO2 concentration
in the atmosphere. This Indian achievement is significant
due to the following.
High population density and low per capita
forest area
India is a large developing country with a population
density of 363 persons/km2. Even more significantly, the
forest area per capita is only 0.06 ha, compared to the world
average of 0.62 ha/capita and Asian average of 0.15 ha/
capita. A comparison of key developing countries and
Western European countries4 is provided in Table 2. Forests
and wooded land area per 1000 population in Germany
and France is nearly two and five times that of India.
Similarly, forest and wooded land in other major developing
countries such as Brazil, China and Indonesia are also
higher by 3 to 40 times, as compared to India.
Low deforestation rate compared to other
developing countries
According to the Global Forest Resources Assessment4,
countries such as India and China are experiencing an increase
in forest area since 1990 (Table 3). However, majority
of the other tropical countries with large area under
forests are experiencing deforestation on a significant
scale since 1990 (Table 3). Majority of the countries (42–
65%) are experiencing reduction in forest area or net deforestation4
(Table 4).
High dependence of human population on forests
In India, nearly 196,000 villages are in the forests or on the
forest fringes. Fuelwood is a dominant source of cooking
energy for the rural population with forests contributing
significantly to this. Apart from fuelwood, village communities
depend on forests for small timber, bamboo and nontimber
forest products.
High livestock density
India accounts for 2.3% of the world’s geographic area,
but accounts for 15% of the global livestock population.
The cattle (cows, bullocks and buffaloes) population density
is nearly one per hectare. When sheep and goats are
included along with cattle, the livestock population density
further increases to 1.5 per hectare. However, if only
forest land is considered, the livestock density is 7 per
hectare, which is among the highest in the world.
Table 2. Comparison of total forest area and forest area/1000 population4
Total area under Forest and wooded
Population Forest area Other wooded forest and wooded land (ha/1000
Country (million) (‘000 ha) land (‘000 ha) land (‘000 ha) population)
India 1079 67,701 4110 71,811 66
China 1326 197,290 87,615 284,905 215
Brazil 178 477,698 0 477,698 2673
Indonesia 217 88,495 0 88,495 406
Germany 82 11,076 0 11,076 134
United Kingdom 59 2845 20 2865 48
France 59 15,554 1708 17,262 287
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 95, NO. 2, 25 JULY 2008 221
Table 3. Comparison of forest area change and deforestation (in ‘000 ha) in other major developing countries4
Net annual change in Area under forest Net annual change in
forest area (‘000 ha) (‘000 ha) forest area (‘000 ha)
Key developing
Region 1990 to 2000 2000 to 2005 countries 1990 2000 2005 1990–2000 2000–2005
Asia –792 1003 China 157,141 177,001 197,290 1986 4058
India 63,939 67,554 67,701 362 29
Indonesia 116,567 97,852 88,495 –1872 –1871
Malaysia 22,376 21,591 20,890 –78 –140
Philippines 10,574 7949 7162 –262 –157
Africa –4375 –4040 Sudan 76,381 70,491 67,546 –589 –589
Zambia 49,124 44,676 42,452 –445 –445
UR Tanzania 41,441 37,318 35,257 –412 –412
Nigeria 17,234 13,137 11,089 –410 –410
South Africa 9203 9203 9203 0 0
South America –3802 –4251 Brazil 520,027 493,213 477,698 –2681 –3103
Argentina 35,262 33,770 33,021 –149 –150
Mexico 69,016 65,540 64,238 –348 –260
Peru 70,156 69,213 68,742 –94 –94
Columbia 61,439 60,963 60,728 –48 –47
Table 4. Countries with positive, negative and zero or marginal annual rate of change in forest area4
Countries with negative Countries with positive Countries with zero net Countries with no
Total number rate of net annual change rate of net annual change annual change in forest significant net annual change
Region of countries in forest area (2000–05) in forest area (2000–05) area (2000–05) in forest area (2000–05)
Asia 48 20 13 12 3
Africa 58 38 8 8 4
South America 15 8 2 3 2 (not available)
Dominance of agrarian economy
Rural areas in India are characterized by large dependence
of the population on land resources, particularly
cropland and forest land, leading to more human pressure
on land.
Implications of Indian forest conservation and
development programmes and policies for global
change
India is a large developing country with a high population
density and low forest area per capita. The livestock
population density is among the highest in the world. Further,
nearly 70% of the population residing in rural areas
depends on forest and other biomass resources for fuelwood,
timber and non-timber forest products for its energy
needs and livelihood. In such a socio-economic
scenario, one would have expected the forest area to decline,
leading to large emissions of CO2 from the forest sector.
The analysis of forest cover, afforestation and reforestation
has shown that the forest cover has stabilized in the
past 15 years (64–67 mha). Projections under the current
trend scenario indicate that the forest cover is likely to
increase in the period 2006–30. Further, model-based
projections of carbon stocks in the Indian forest sector
show a likely increase (from 8.79 GtC in 2005 to 9.75 GtC
in 2030). This is a significant achievement for a developing
country such as India, despite high human and livestock
population density, high dependence of rural
communities on forests for biomass resources and low per
capita forest area. The factors contributing to the current
and projected trends of stable or increasing carbon stocks
in the forests are progressive and effective forest conservation
legislations, afforestation and reforestation programmes
and community participation in forest protection,
regeneration and management.
The progressive conservation-oriented forest policies
and afforestation programmes are contributing to reduction
in CO2 emissions to the atmosphere, stabilization of
carbon stocks in forests and conservation of biodiversity.
Thus, the Indian forest sector is projected to keep making
positive contributions to global change and sustainable
development. This projected estimate and conclusion excludes
any potential decline in forest carbon stocks due to
forest conversion, forest degradation, biomass extraction,
fire, etc.
RESEARCH ARTICLES
CURRENT SCIENCE, VOL. 222 95, NO. 2, 25 JULY 2008
1. Ministry of Environment and Forests, India’s Initial National
Communication to UNFCCC (NATCOM), New Delhi, 2004;
available at http://www.natcomindia.org/natcomreport.htm
2. http://envfor.nic.in/nfap/, accessed on 11 July 2007.
3. Forest Survey of India, State of Forest Report 2003, Ministry of
Environment and Forests, Dehra Dun.
4. FAO, State of the World’s Forests, Rome, 2005.
5. Forest Survey of India, State of Forest Report 1987, Ministry of
Environment and Forests, Dehra Dun.
6. Forest Survey of India, State of Forest Report 2001, Ministry of
Environment and Forests, Dehra Dun.
7. Forest Survey of India, State of Forest Report 1989, Ministry of
Environment and Forests, Dehra Dun.
8. Forest Survey of India, State of Forest Report 1991, Ministry of
Environment and Forests, Dehra Dun.
9. Forest Survey of India, State of Forest Report 1993, Ministry of
Environment and Forests, Dehra Dun.
10. Forest Survey of India, State of Forest Report 1995, Ministry of
Environment and Forests, Dehra Dun.
11. Forest Survey of India, State of Forest Report 1997, Ministry of
Environment and Forests, Dehra Dun.
12. Forest Survey of India, State of Forest Report 1999, Ministry of
Environment and Forests, Dehra Dun.
13. Sathaye, J. and Meyers, S., Greenhouse Gas Mitigation Assessment:
A Guidebook, Kluwer, Dordrecht, The Netherlands, 1995.
14. Ravindranath, N. H. et al., Methodological Issues in forestry mitigation
projects: A case study of Kolar district. Miti. Adap. Strat.
Global Change, 2007, 12, 1077–1098.
15. Ravindranath, N. H., Sudha, P. and Sandhya, R., Forestry for sustainable
biomass production and carbon sequestration in India.
Miti. Adap. Strat. Global Change, 2001, 6, 233–256.
16. Richards, J. F. and Flint, E. P., Historic land use and carbon estimates
for South and Southeast Asia 1880–1980. ORNL/CDIAC-
61, NDP-046, Oak Ridge National Laboratory, Tennessee, USA,
1994.
17. Ravindranath, N. H., Somashekhar, B. S. and Gadgil, M., Carbon
flows in Indian forests. Climate Change, 1997, 35, 297–320.
18. Chhabra, A. and Dadhwal, V. K., Assessment of major pools and
fluxes of carbon in Indian forests. Climate Change, 2004, 64, 341–
360.
19. Haripriya, G. S., Carbon budget of the Indian forest ecosystem. Climate
Change, 2003, 56, 291–319.
ACKNOWLEDGEMENTS. We thank the MOEF, GOI for supporting
this project as well as climate change research activities at the Centre
for Ecological Sciences, Indian Institute of Science, Bangalore. We
also thank Jayant Sathaye and Ken Andrasko for their support in our
climate change research over the years.
Received 12 July 2007; revised accepted 22 May 2008
Erratum
Sago starch: An economical substitute for in vitro primary screening of starch utilizing microorganisms
R. B. Binky, R. Saikiran, S. Tushar, P. Umesh, J. Yogesh and A. N. Syed
[Curr. Sci., 2007, 93, 459–461]
Line 1, para 2, 2nd column should have been:
1. Successful use of isabgol derived from Plantago ovata seeds, gum katira exuded from Cochlospermum religiosum
bark and guar gum from endosperm of Cyamopsis tetragonoloba as gelling agent has been reported for microbial
culture media3,6,7.
2. Nene, Z. L. in ref. 6 should have been Nene, Y. L.
We regret the error.
—Authors
[http://en.wikipedia.org/wiki/Tropical_rainforest Wikipedia - Tropical Rainforests]
A '''tropical rainforest''' is an ecosystem usually found around the equator. They are common in Asia, Australia, Africa, South America, Central America, Mexico and on many of the Pacific Islands. Within the World Wildlife Fund's biome classification, tropical rainforests are considered a type of tropical wet forest (or tropical moist broadleaf forest) and may also be referred to as ''lowland equatorial evergreen rainforest''. Minimum normal annual rainfall between convert|1750|mm|in and convert|2000|mm|in occurs in this climate region. Mean monthly temperatures exceed convert|18|C|F during all months of the year.[1] Rainforests are home to half of all the living animal and plant species on the planet.<ref name="MI">The Regents of the University of Michigan. [http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/rainforest/rainforest.html The Tropical Rain Forest.] Retrieved on 2008-03-14.</ref> Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[2] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[3] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[4]
Characteristics
The rainforests are home to more species or populations than all other biomes combined. 82% of the world's biodiversity are found in tropical rainforests.[5] The leafy tops of tall trees - extending from 50 to 85 meters above the forest floor - forms an understory. Organic matter that falls to the forest floor quickly decomposes, and the nutrients are recycled.Rainforests are characterized by high rainfall. This often results in poor soils due to leaching of soluble nutrients. Oxisols, as are the soils of many seasonally flooded forests, which are annually replenished with fertile silt.
Tropical rain forests have been subjected to heavy logging and agricultural clearance throughout the 20th century, and the area covered by rainforests around the world is rapidly shrinking.[6] [7]
Rainforests are also often called the "Earth's lungs," however there is no scientific basis for such a claim as tropical rainforests are known to be essentially oxygen neutral, with little or no net oxygen production.[8] [9]
Tall, broad-leaved evergreen trees are the dominant plants, forming a leafy canopy over the forest floor. Taller trees, called emergents, may rise above the canopy. The upper portion of the canopy often supports a rich flora of epiphytes, including orchids, bromeliads, mosses, and lichens, who live attached to the branches of trees. The undergrowth or understory in a rain forest is often restricted by the lack of sunlight at ground level, and generally consists of shade-tolerant shrubs, herbs, ferns, small trees, and large woody vines which climb into the trees to capture sunlight. The relatively sparse under story vegetation makes it possible for people and other animals to walk through the forest. In deciduous and semi-deciduous forests, or forests where the canopy is disturbed for some reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called jungle.
The temperature ranges from 15 to 50 °C and 125 to 660 cm of rainfall yearly.
Layers
The rainforest is divided into five different parts, each with different plants and animals, adapted for life in the particular area. These are: the floor layer, the shrub layer, the undercanopy layer, the canopy layer and the emergent layer. Only the emergent layer is unique to tropical rainforests, while the others are also found in temperate rainforests.The emergent layer contains a small number of very large trees which grow above the general canopy, reaching heights of 45-55 m, although on occasion a few species will grow to 70 m or 80 m tall. They need to be able to withstand the hot temperatures and strong winds. Eagles, butterflies, bats and certain monkeys inhabit this layer.
Canopy - This is the primary layer of the forest and forms a roof over the two remaining layers. Most canopy trees have smooth, oval leaves that come to a point. It's a maze of leaves and branches. Many animals live in this area since food is abundant. Those animals include: snakes, toucans and tree frogs.
Under canopy - Little sunshine reaches this area so the plants have to grow larger leaves to reach the sunlight. The plants in this area seldom grow to 12 feet. Many animals live here including jaguars, red-eyed tree frogs and leopards. There is a large concentration of insects here.
Shrub layer/forest floor - This layer is very dark. Almost no plants grow in this area, as a result. Since hardly any sun reaches the forest floor things begin to decay quickly. A leaf that might take one year to decompose in a regular climate will disappear in 6 weeks. Giant anteaters live in this layer.
Human uses
Habitation
Tropical rainforests are unable to support human populations.<ref name="Bailey">Bailey, R.C., Head, G., Jenike, M., Owen,B., Rechtman, R., Zechenter, E., 1989 "Hunting and gathering in tropical rainforest: is it possible." American Anthropologist, 91:1 59-82</ref> Food resources within the forest are extremely dispersed due to the high biological diversity and what food does exist is largely restricted to the canopy and requires considerable energy to obtain. Some groups of hunter-gatherers have exploited rainforest on a seasonal basis but dwelt primarily in adjacent savanna and open forest environments where food is much more abundant. Other peoples described as rainforest dwellers are hunter-gatherers who subsist in large part by trading high value forest products such as hides, feathers, and honey with agricultural people living outside the forest.<ref name="Bailey"/>Conversion to agricultural land
With the invention of agriculture humans were able to clear sections of rainforest to produce crops, converting it to open farmland. Such people, however, obtain their food primarily from farm plots cleared from the forest <ref name="Bailey"/>[10] and hunt and forage within the forest to supplement this.Agriculture on formerly forested land is not without difficulties. Rainforest soils are often thin and leached of many minerals, and the heavy rainfall can quickly leach nutrients from area cleared for cultivation. People such as the Yanomamo of the Amazon, utilise slash-and-burn agriculture to overcome these limitations and enable them to push deep into what were previously rainforest environments. However, these are not rainforest dwellers, rather they are dwellers in cleared farmland<ref name="Bailey"/>[11] that make forays into the rainforest and up to 90% of the typical Yanamomo diet comes from farmed plants.[12]
Cultivated foods and spices
Coffee, chocolate, banana, mango, papaya, macadamia, avocado, and sugarcane all originally came from tropical rainforest and are still mostly grown on plantations in regions that were formerly primary forest. In the mid-1980s and 90s, 40 million tons of bananas were consumed worldwide each year, along with 13 million tons of mangoes. Central American coffee exports were worth US$3 billion in 1970. Much of the genetic variation used in evading the damage caused by new pests is still derived from resistant wild stock. Tropical forests have supplied 250 cultivated kinds of fruit, compared to only 20 for temperate forests. Forests in New Guinea alone contain 251 tree species with edible fruits, of which only 43 had been established as cultivated crops by 1985.[13]Pharmaceutical and biodiversity resource
Tropical rainforests are called "the world's largest pharmacy"cn because of the large amount of natural medicines discovered in rainforests that are derived from rainforest plants. For example, rain forests contain the "basic ingredients of hormonal contraception methods, cocaine, stimulants, and tranquilizing drugs" (Banks 36)cn. Curare (a paralyzing drug) and quinine (a malaria cure) are also found there.Tourism
Tourism in tropical rainforests has increased over the years having both positive and negative effects.Fact|date=September 2008 People travel both nationally and internationally to experience rain forests firsthand.Positive Impacts
Despite the negative effects of tourism in the tropical rainforests, there are also several important positive effects.
*An increase in tourism has increased economic support, allowing more revenue to go into the protection of the habitat. Tourism can contribute directly to the conservation of sensitive areas and habitat. Revenue from park-entrance fees and similar sources can be utilised specifically to pay for the protection and management of environmentally sensitive areas. Revenue from taxation and tourism provides an additional incentive for governments to contribute revenue to the protection of the forest.
*Tourism also has the potential to increase public appreciation of the environment and to spread awareness of environmental problems when it brings people into closer contact with the environment. Such increased awareness can induce more environmentally conscious behavior. Tourism has had a positive effect on wildlife preservation and protection efforts, notably in Africa but also in South America, Asia, Australia, and the South Pacific.[14]
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References
reflist*Mann, Charles C., ''1491 New Revelations of the Americas Before Columbus'' New York: Knopf, 2005 ISBN 0739464418
See also
External links
commonscat|Rainforests*[http://www.ran.org Rainforest Action Network]
*[http://www.worldwildlife.org/wildplaces/amazon/index.cfm?sc=AWY0707WCG00&searchen=google Info on Amazon Rainforest, the largest rainforest in the world]
*[http://www.blueplanetbiomes.org/rainforest.htm Rain Forest Info from Blue Planet Biomes]
*[http://passporttoknowledge.com/rainforest/main.html Passport to Knowledge Rainforests]
*[http://www.coolearth.org Rainforest protection]
Conservation efforts
There have been many conservation efforts:*[http://www.worldwildlife.org World Wildlife Fund]
[http://www.worldwildlife.org/wildplaces/amazon/you_do.cfm Amazon - What you can do]
*[http://www.greenpeace.org Greenpeace]
[http://www.greenpeace.org/international/campaigns/forests Protect Ancient Forests]
*[http://www.coolearth.org Cool Earth]
[http://www.coolearth.org/298/coolearth-31/get-involved-149/get-involved-326.html A million little acres]
Category/Rainforests
Category/Tropics
Category/Biomes
Category/Ecosystems
Link FA|he
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http://www.fs.fed.us/global/lzone/student/tropical.htm
T he world's tropical forests circle the globe in a ring around the Equator They are surprisingly diverse, ranging from lush rain forests to dry savannas and containing millions of species of plants and animals (fig. 1). Tropical forests once covered some 15.3 billion acres (6.2 billion ha). In recent times, however, they have been cut at a rapid rate to make room for agriculture and to obtain their many valuable products. Between 1985 and 1990, 210 million acres (85 million ha) of tropical forests were destroyed.
This guide shows how modern forest practices can help stem the tide of forest destruction while providing valuable forest products for people. The tropical forests of Puerto Rico, which were abused for centuries, were badly depleted by the early 1900's. Widespread abandonment of poor agricultural lands has allowed natural reforestation and planting programs to create a patchwork of private, Commonwealth, and Federal forests across the land (fig. 2). The most frequent example in this publication is the Luquillo Experimental Forest, which could be a model for protecting and managing tropical forests worldwide.
About half of all the world's forests are in the Tropics, the area between the Tropic of Cancer and the Tropic of Capricorn. This region may be best known for its rain forests - lush, steamy jungles with towering trees, epiphytes, and dense under stories of smaller trees, shrubs, and vines.
Tropical forests are surprisingly diverse. In addition to rain forests, there are mangroves, moist forests, dry forests, and savannas. Such classifications, however, give only a slight indication of the diversity of tropical forests. One study by the Food and Agriculture Organization (FAO) of the United Nations, which considered 23 countries in tropical America, 37 in tropical Africa, and 16 in tropical Asia, identified dozens of types of tropical forests: open and closed canopy forests, broadleaved trees and conifer forests , closed forests and mixed forest grasslands, and forests where agriculture has made inroads.
Rain Forests**
The largest remaining areas of tropical rain forests are in Brazil, Congo, Indonesia, and Malaysia. Precipitation generally exceeds 60 inches (150 cm) per year and may be as high as 400 inches (1000 cm). Lowland rain forests are among the
Mangrove forests grow in the swampy, intertidal margin between sea and shore and are often considered part of the rain forest complex. The roots of mangrove trees help stabilize the shoreline and trap sediment and decaying vegetation that contribute to ecosystem productivity (fig. 3).
Dry Forests
Large areas of tropical dry forests are found in India, Australia, Central and South America, the Caribbean, Mexico, Africa, and Madagascar. Dry forests receive low rainfall amounts, as little as 20 inches (50 cm) per year, and are characterized by species well adapted to drought. Trees of dry tropical forests are usually
Savanna is a transitional type between forest and grassland. Trees are often very scattered and tend to be well adapted to drought and tolerant of fire and grazing. If fire is excluded, trees eventually begin to grow and the savanna is converted to dry forest. With too much fire or grazing, dry forest becomes savanna (fig. 4). This vegetation type has fewer species of trees and shrubs but more grasses and forbs than other forest types in the Tropics.
All forests have both economic and ecological value, but tropical forests are especially important in global economy. These forests cover less than 6 percent of the Earth's land area, but they contain the vast majority of the world's plant and animal genetic resources. The diversity of life is astonishing. The original forests of Puerto Rico, for example, contain more than 500 species of trees in 70 botanical families. By comparison, temperate forests have relatively few. Such diversity is attributed to variations in elevation, climate, and soil, and to the lack of frost.
Wood and Other Products
Tropical forests provide many valuable products including rubber, fruits and nuts, meat, rattan, medicinal herbs, floral greenery, lumber, firewood, and charcoal. Such forests are used by local people for subsistence hunting and fishing. They provide income and jobs for hundreds of millions of people in small, medium, and large industries.
Other Economic Values
Tropical forests are home for tribal hunter-gatherers whose way of life has been relatively unchanged for centuries. These people depend on the forests for their livelihood. More than 2.5 million people also live in areas adjacent to tropical forests. They rely on the forests for their water, fuelwood, and other resources and on its shrinking land base for their shifting agriculture. For urban dwellers, tropical forests provide water for domestic use and hydroelectric power. Their scenic beauty, educational value, and opportunities for outdoor recreation support tourist industries.
Many medicines and drugs come from plants found only in tropical rain forests. Some of the best known are quinine, an ancient drug used for malaria; curare, an anesthetic and muscle relaxant used in surgery; and rosy periwinkle, a treatment for Hodgkin's disease and leukemia. Research has identified other potential drugs that may have value as contraceptives or in treating a multitude of maladies such as arthritis, hepatitis, insect bites, fever, coughs, and colds. Many more may be found. In all, only a few thousand species have been evaluated for their medicinal value.
In addition, many plants of tropical forests find uses in homes and gardens: ferns and palms, the hardy split-leaf philodendron, marantas, bromeliads, and orchids (fig. 8), to name just a few.
Environmental Benefits
Tropical forests do more than respond to local climatic conditions; they actually influence the climate. Through transpiration, the enormous number of plants found in rain forests return huge amounts of water to the atmosphere, increasing humidity and rainfall, and cooling the air for miles around. In addition, tropical forests replenish the air by utilizing carbon dioxide and giving off oxygen. By fixing carbon they help maintain the atmospheric carbon dioxide levels low and counteract the global "greenhouse" effect.
Forests also moderate stream flow. Trees slow the onslaught of tropical downpours, use and store vast quantities of water, and help hold the soil in place. When trees are cleared, rainfall runs off more quickly, contributing to floods and erosion.
Before the dawn of agriculture approximately 10,000 years ago, forests and open woodland covered about 15.3 billion acres (6.2 billion ha) of the globe. Over the centuries, however, about one-third of these natural forests has been destroyed. According to a 1982 study by FAO, about 27.9 million acres (11.3 million ha) of tropical forests are cut each year-an area about the size of the States of Ohio or Virginia. Between 1985 and 1990, an estimated 210 million acres (85 million ha) of tropical forests were cut or cleared. In India, Malaysia, and the Philippines, the best commercial forests are gone, and cutting is increasing in South America. If deforestation is not stopped soon, the world will lose most of its tropical forests in the next several decades.
Reasons for Deforestation
Several factors are responsible for deforestation in the Tropics: clearing for agriculture, fuelwood cutting, and harvesting of wood products. By far the most important of these is clearing for agriculture. In the Tropics, the age-old practice of shifting, sometimes called "slash-and-burn," agriculture has been used for centuries. In this primitive system, local people cut a small patch of forest to make way for subsistence farming. After a few years, soil fertility declines and people move on, usually to cut another patch of trees and begin another garden.
In the abandoned garden plot, the degraded soil at first supports only weeds and shrubby trees. Later, soil fertility and trees return, but that may take decades. As population pressure increases, the fallow (rest) period between cycles of gardening is shortened, agricultural yields decrease, and the forest region is further degraded to small trees, brush, or eroded savanna.
Conversion to sedentary agriculture is an even greater threat to tropical forests. Vast areas that once supported tropical forests are now permanently occupied by subsistence farmers and ranchers and by commercial farmers who produce sugar, cocoa, palm oil, and other products.
In many tropical countries there is a critical shortage of firewood. For millions of rural poor, survival depends on finding enough wood to cook the evening meal. Every year more of the forest is destroyed, and the distance from home to the forest increases. Not only do people suffer by having to spend much of their time in the search for wood, but so does the land. Damage is greatest in dry tropical forests where firewood cutting converts forests to savannas and grasslands.
The global demand for tropical hardwoods, an $8-billion-a-year industry, also contributes to forest loss. Tropical forests are usually selectively logged rather than clear-cut. Selective logging leaves the forest cover intact but usually reduces its commercial value because the biggest and best trees are removed. Selective logging also damages remaining trees and soil, increases the likelihood of fire, and degrades the habitat for wildlife species that require large, old trees-the ones usually cut. In addition, logging roads open up the forests to shifting cultivation and permanent settlement.
In the past, logging was done primarily by primitive means-trees were cut with axes and logs were moved with animals such as oxen. Today the use of modern machinery--chain saws, tractors, and trucks -makes logging easier, faster, and potentially more destructive.
Endangered Wildlife
Forests are biological communities-complex associations of trees with other plants and animals that have evolved together over millions of years. Because of the worldwide loss of tropical forests, thousands of species of birds and animals are threatened with extinction. The list includes many unique and fascinating animals, among them the orangutan, mountain gorilla, manatee, jaguar, and Puerto Rican parrot. Although diverse and widely separated around the globe, these specles have one important thing in common. They, along with many other endangered species, rely on tropical forests for all or part of their habitat.
Orangutans (Pongo pygmaeus) are totally dependent on small and isolated patches of tropical forests remaining in Borneo and Sumatra, Indonesia. Orangutans spend most of their time in the forest canopy where they feed on leaves, figs and other fruit, bark, nuts, and insects. Large trees of the old-growth forests support woody vines that serve as aerial ladders, enabling the animals to move about, build their nests, and forage for food. When the old forests are cut, orangutans disappear.
The largest of all primates, the gorilla, is one of man's closest relatives in the animal kingdom. Too large and clumsy to move about in the forest canopy, the gorilla lives on the forest floor where it forages for a variety of plant materials. Loss of tropical forests in central and west Africa is a major reason for the decreasing numbers of mountain gorillas (Gorilla gorilla). Some habitat has been secured, but the future of this gentle giant is in grave danger as a result of habitat loss and poaching.
The jaguar (Leo onca), a resident of the Southwestern United States and Central and South America, is closely associated with forests. Its endangered status is the result of hunting and habitat loss.
In addition to species that reside in tropical forests year round, others depend on such forests for part of the year. Many species of migrant birds journey 1,000 miles or more between their summer breeding grounds in the north and their tropical wintering grounds. These birds are also threatened by tropical forest destruction.
Forestry-loosely defined as the systematic management and use of forests and their natural resources for human benefit-has been practiced for centuries. Most often, forestry efforts have been initiated in response to indiscriminate timber cutting that denuded the land and caused erosion, floods, or a shortage of wood products.
Ancient Forestry Practices
In ancient Persia (now Iran), forest protection and nature conservation laws were in effect as early as 1,700 B.C. Two thousand years ago the Chinese practiced what they called "four sides" forestry-trees were planted on house side, village side, road side, and water side. More than 1,000 years ago, Javanese maharajahs brought in teak and began to cultivate it. In the African Tropics, agroforestry (growing of food crops in association with trees) has been practiced for hundreds of years.
In the Yucatan Peninsula of southern Mexico, the ancient Mayas cultivated fruit and nut trees along with such staples as corn, beans, and squash. Bark, fibers, and resin were obtained from plants grown in fields, kitchen gardens, and orchards. Early in their civilization, the Mayas practiced slash-and-burn agriculture. As their population grew, they found more efficient methods of growing crops. They terraced hillsides, learned how to decrease the time between "rotations" of agricultural land with native forests, dug drainage channels and canals to move water to and from cultivated areas, and filled in swampland to plant crops.
The agricultural sophistication of the Mayas enabled their civilization to grow and flourish. What brought about their decline about A.D. 820 is not fully known, but some believe that as their society developed, the Mayas made unsustainable demands on their environment.
Relatively little is known about tropical forestry before the mid1800's in most places. At that time, the European colonial empiresnotably the Dutch, English, and Spanish-brought modern forest management practices to Indonesia, India, Africa, and the Caribbean. Centers for forestry and forestry research were established, and more careful records were kept.
Sustainable Forestry
Modern forestry has its basis in 18th-century Germany. Like the Chinese and the Mayan forest practices, German forestry is essentially agricultural. Trees are managed as a crop. Two concepts are important: renewability and sustainability. Renewability means that trees can be replanted and seeded and harvested over and over again on the same tract of land in what are known as crop "rotations." Sustainability means that forest harvest can be sustained over the long term. How far into the future were foresters expected to plan? As long as there were vast acres of virgin (original) forests remaining, this question was somewhat academic. Today, however, sustainability is a vital issue in forestry. Most of the world's virgin forests are gone, and people must rely more and more on second- growth or managed forests. Perhaps we now face, as never before, the limits to long-term productivity.
In the German forest model, forestry is viewed as a continual process of harvest and regeneration. Harvest of wood products is a goal, but a forester's principal tasks are to assure long-term productivity. That is achieved by cutting the older, mature, and slow-growing timber to make way for a new crop of young, fast-growing trees.
Harvest-Regeneration Methods
Three examples of timber harvest-regeneration methods (silvicultural systems) illustrate how foresters manage stands to produce timber on a sustained basis.
Selection
Individual trees or small groups of trees are harvested as they become mature. Numerous small openings in the forest are created in which saplings or new seedlings can grow. The resulting forest has a continuous forest canopy and trees of all ages. Such systems favor slow-growing species that are shade tolerant.
Clearcutting
In clearcutting, an entire stand of trees is removed in one operation. From the forester's point of view, clearcutting is the easiest way to manage a forest-and the most economical. Regeneration may come from sprouts on stumps, from seedlings that survive the logging operation, or from seeds that germinate after the harvest. If natural regeneration is delayed longer than desired, the area is planted or seeded.
Clearcutting systems are often used to manage fast-growing species that require a lot of light. Resulting stands are even aged because all the trees in an area are cut-and regenerated-at the same time. Clearcutting has become controversial in recent years because it has the potential to damage watersheds and because it tends to eliminate species of wildlife dependent on old growth trees. If clearcuts are kept small and the cutting interval is long enough, however, biological diversity may not be impaired.
Shelterwood
In shelterwood systems, the forest canopy is removed over a period of years, usually in two cuttings. After the first harvest, natural regeneration begins in the understory. By the time the second harvest is made, enough young trees have grown to assure adequate regeneration. Shelterwood systems favor species that are intermediate in tolerance to shade. Such systems are difficult to use successfully and are the least used of the three silvicultural methods described.
Multiple-Use Forestry
Gifford Pinchot, the first Chief of the U.S. Forest Service, was also this country's first professional forester. Pinchot advocated the use of forest resources-all resources, not just timber-for human benefit. Pinchot was a strong and charismatic leader, and his ideas helped shape the course of forestry in the United States.
Pinchot had a vocal opponent in John Muir, a young naturalist from California who believed that public lands should be preserved rather than used. Eventually Muir and Pinchot became rivals for public approval. Oddly enough, there was no
loser in this early conservation battle. Muir's preservation ethic became embodied in the philosophy of the National Parks, and Pinchot's concept of wise use became the guiding principle of the National Forests.
National Forests are still managed under the concepts of multiple use and sustained yield. The dominant uses of National Forests are considered to be wood, water, wildlife, forage (for domestic cattle and wildlife), and recreation. Extraction of minerals and other valuable products is also considered a legitimate use of National Forests. Because Pinchot's philosophy left room for the "highest and best use" of a given area, the U.S. National Forests now include a wilderness system of more than 32 million acres (13 million ha) in which timber harvest is not allowed.
Today it is generally recognized that most, if not all, nondestructive uses of forest are valid. Some areas may be set aside as parks; others for wildlife habitat or as wilderness. Still others will be managed for timber harvest or multiple benefits. Today, conflicts arise primarily over where these different uses will be dominant. In the National Forests, such decisions are made through a land-use planning process in which the public has ample opportunities for input and involvement.
At the turn of the century, very little was known about the world's native forests or how to manage them. In the United States, foresters were quick to recognize the value of information about forests and a branch of research was established in the Forest Service in 1915. Early research was done primarily in support of reforestation efforts, but, as forestry grew in size and complexity, so did the research.
Today, the USDA Forest Service has six regional experiment stations located in important forest regions. Each experiment station has several field laboratories generally with specialized assignments for a geographic region or a specific subject area, and numerous sites for field research. In addition, the Forest Products Laboratory in Madison, WI, serves as a nationwide center for research and development of new technology relating to wood , including tropical woods. Two laboratories are dedicated exclusively to tropical forest research: the International Institute of Tropical Forestry in Puerto Rico and the Institute of Pacific Islands Forestry in Hawaii.
Research is vital for modern forest management, which is information intensive. Today's foresters require vast quantities of data and a knowledge of ecology: they must understand not only the parts of ecosystems but how different parts of the environment interact. Scientific investigations are conducted in support of all kinds of forestry activities: silviculture, forest insect and disease control, wildlife habitat management, fire prevention and control, range and watershed management, forest products utilization, forest survey, reforestation, ecology, and economics.
In the past, timber harvest in the Tropics has seldom been followed by regeneration. Conversion to agriculture is often permanent or results in soil erosion. Timber harvest contracts have usually been short term and have provided little or no incentive for timber companies to replant. So little reforestation has been done in the Tropics that many people believe these forests cannot be restored. However, there are many examples of successful reforestation in India, Indonesia, and the Caribbean.
In the Tropics, as elsewhere, forestry is a mixture of modern innovations and ancient techniques borrowed from local tradition. Plantation forestry is common. Forest reserves have been established for timber harvest, wildlife habitat, scenery, outdoor recreation, or watershed protection. And in the Tropics, agroforestry-tree growing combined with agricultural cropping-is much more common than elsewhere.
Plantation Forestry
In the Tropics, trees are often planted and grown in plantations for wood production. Often, many species must be tried to determine which will grow best (fig. 10). Plantations must also be supported by major investments in forest management and research. Forest nurseries must be established, and planting techniques and cultural practices (spacing and thinning, pruning, fertilization, insect and disease control, and genetic improvement) must be developed.
Extensive pine plantations have been established in the moist Tropics, mainly in South Africa and Australia. Species most often planted include Caribbean pine (Pinus caribaea), ocote pine (P. oocarpa), slash pine (P. elliottii), and benguet pine (P. kesiya). Pines are popular plantation trees because they are generally fast growing, have good survival rates, and are adapted to a wide variety of environments, including degraded forest sites.
Eucalypts, including species such as Eucalyptus grandis, E. deglupta, E. tereticornis, E. globulus, and E. camaldulensis are favored for the same reasons. Eucalypts are commonly grown for pulp, fuel, and lumber. Other species commonly planted include teak (Tectona grandis), Honduras mahogany (Swietenia macrophylla), melina (Gmelina arborea) beefwood (Casuarina equisetifolia), and Mexican cypress (Cupressus lusitanica).
Forest Reserves
Perhaps the most famous of these reserves is the 5,600 square mile (14,500 k squared) Serengeti National Park in Tanzania. With its vast herds of grazing ungulates (hoofed animals) and predators, including several endangered species, the Serengeti is a showcase of a savanna ecosystem that has long been protected and managed for wildlife and other natural resources (fig. 11). Although plagued with poachers, the Serengeti promotes the cause of wildlife conservation to the many thousands of "ecotourists" who pay to experience nature each year.
Another type of forest reserve is the "extractive" reserve, which is dedicated to the production of useful products. Large reserves of this type have been established recently in Brazil. Local residents use them for tapping rubber, for gathering fruits and nuts, for hunting, and for harvesting wood on a sustained yield basis. Such uses provide a sustainable income while maintaining the ecological integrity of the forest.
Agroforestry
The practice growing of trees in combination with agricultural crops is fairly common in the Tropics. It is possible to grow food crops year around in many forested areas, and rural poor depend on this source of food as nowhere else on Earth.
Taungya System
Various systems have been developed for combining forestry with agriculture. "Taungya" is a Burmese word meaning cultivated hill plot. This system of agroforestry was developed in Europe during the Middle Ages and probably indepenently in a number of places in the Tropics. After existing forest or ground cover is removed by burning, trees are planted along with agricultural crops. Both are cultivated until the tree canopy closes. Then the area is left to grow trees, and another site is located for combined forestry agriculture.
Shade Cropping
An overstory of trees is often used to provide shade for agricultural crops. A common practice is to grow tree species such as guaba Inga vera) over coffee. In Puerto Rico, many forests developed where coffee was once grown in this manner.
Support Crops
Trees can be planted to provide support (and sometimes shade) for vine crops. Vines such as pepper and vanilla need support.
Alley Cropping
Nitrogen-fixing trees are planted in hedges in widely-space parallel rows along the contour of slopes. Food crops are grown in the "alley" between the rows. The trees add nitrogen and organic matter, protect the soil from erosion, and provide wood and animal forage.
Living Fences
Green fenceposts that will root and sprout often are planted in a closely spaced row. When they sprout, they create a "living fence" that provides shade and forage for cattle.
Windbreaks
Trees are often planted as windbreaks for agricultural crops, farms, or homesites. Such plantings can eventually contribute wood products as well as shelter. Food trees such as citrus, rubber, and mango can also provide fuel, lumber, and other wood products when they have outlived their original usefulness.
The conservation issues of the past seem simple compared with those of today. As we move toward the 21st century, human societies are concerned with global warming, deforestation, species extinction, and rising expectations. Growing populations must be fed, clothed, and sheltered, and people everywhere want higher standards of living.
Global Warming
Warming of the earth's atmosphere is a major environmental issue. Air pollution, deforestation, and widespread burning of coal, oil, and natural gas have increased atmospheric concentrations of carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. These gases trap heat from the sun and prevent it from radiating harmlessly back into space. Thus, the 64 greenhouse" or warming effect is created.
Because of natural variations in climate, it is difficult to measure warming over large areas. Scientists agree, however, that increases in atmospheric concentrations of greenhouse gases will cause higher temperatures worldwide. Even an increase of a few degrees might cause serious melting of the polar icecaps, a gradual rise in sea level, a disruption in normal weather patterns, a possible increase in forest fires, and the extinction of species.
Role of Forests
Trees, the largest of all land plants, act as a kind of environmental "buffer" for the ecosystem they dominate. They help ameliorate the extremes of climate (heat, cold, and wind) and create an environment where large land mammals, including people, can live comfortably. Trees complement animals in the global environment. Mammals take in oxygen from the air and exhale carbon dioxide. Plants use the carbon dioxide in their growth processes, store the carbon in woody tissues, and return oxygen to the atmosphere as a waste product. This process, known as photosynthesis, is essential to life. Carbon captured from the atmosphere by photosynthesis is eventually recycled through the environment in a process known as the carbon cycle. Trees have an especially important role in the carbon cycle. Tree leaves also act as filters to remove atmospheric pollutants from the air. This effect is particularly beneficial in urban areas.
Forestry Issues
Two key issues will dominate forestry in the years ahead: (1) maintaining long-term productivity of managed forests, and (2) preventing further loss of tropical forests. Both problems will require new approaches to forest management.
Traditionally, forestry has focused on growing crops of wood in plantations or in managed natural stands. In this "agricultural mode," other benefits of forest such as watershed protection, wildlife habitat, climate moderation, and outdoor recreation, have received less attention than wood production.
Perhaps more importantly, the sustainability of the full range of forest benefits has not been measured. There is no question that trees can be grown for crops of wood in managed stands. With intensive management-short rotations, species selection, genetic improvement, fertilization, thinning, and other cultural treatments-more wood can be produced in less time than in natural forests. But for how long? And at what cost in other benefits?
Since the 1930's when timber harvests were curtailed, the forests have been managed primarily for watershed protection, wildlife habitat, and outdoor recreation.
There are no easy solutions to the problem of tropical forest destruction, but most experts agree that the problems cannot be solved simply by locking up the forests in reserves. The forests are too important to local people for that to be a workable solution. There is no doubt that tropical forests will be cut. It is better for them to be cut in an ecologically sound manner than to be cleared for poor-quality farmland or wasted by poor harvest practices (fig. 12).
The only real long-term solutions are: (1) more efficient agriculture on suitable farmland, (2) efficient forestry practice including plantations, and (3) reserves to protect species and ecosystems. Many forestry experts believe that we have only begun to tap the potential for wise use of tropical forests. Many uses have yet to be fully explored. We are only starting to learn the value of tropical forests for medicines, house and garden plants, food and fiber, tourism, and natural resource education.
Jeremy
Here is a site that answers Question "a","c", and touch a little on "b"and "d" ...
[[http://saferenvironment.wordpress.com/2008/08/20/rainforest-conservation-%E2%80%93-challenges-of-addressing-deforestation-issues/|]]http://saferenvironment.wordpress.com/2008/08/20/rainforest-conservation-%E2%80%93-challenges-of-addressing-deforestation-issues/
and here is some content...
The rainforest biome (a major habitat type) can be defined as forest growing in regions with more than 200 cm (6.5 feet) of rainfall per year. Although there are temperate rainforests (such as that of British Columbia in Canada), tropical rainforests occur between the Tropic of Cancer and the Tropic of Capricorn (23.5o N and 23.5o S). They are found in regions where the average temperatures of the three warmest and the three coldest months do not differ by more than 5o C, although there may be daily variations of more than that. Rainfall is relatively evenly distributed, which allows the growth of a heavy canopy of broad-leaved evergreen tree.
The rainforests are home to more than half the animals in the world. Rainforest animals reside in all four strata of the forest. ‘Strata’ means ‘layers’. Scientists divide rainforests into different strata (or layers) for easy reference. Each of these layers is a very different environment and supports different life forms. The strata differ in many ways, including temperature, the amount of sunlight that they receive, the wetness of the environment and the amount and types of life forms living in it.
Today tropical rainforests are disappearing from the face of the globe more rapidly than anything else. As per the estimation, despite growing international concern, rainforests continue to be destroyed at a pace exceeding 80,000 acres (32,000 hectares) per day. World rainforest cover now stands at around 2.5 million square miles (6 million square kilometers), representing around 5 percent of the world’s land surface. Unfortunately, much of this remaining area has been impacted by human activities and no longer retains its full original biodiversity. Deforestation of tropical rainforests has a global impact through species extinction, the loss of important ecosystem services and renewable resources, and the reduction of carbon sinks. The problem must be remedied, but the means are not as simple as fortifying fences around the remaining rainforests or banning the timber trade. Economic, political, and social pressures are not allowing rainforests to persist.
Forces behind rainforest loss – Countries with significant rainforest cover are generally among the world’s poorest. Therefore, rainforests are being cut mostly for economic reasons, though there are political and social motivations as well. A significant portion of deforestation is caused by poor farmers simply trying to eke out a living on marginal lands. Beyond conversion for subsistence agriculture, activities like logging, clearing for cattle pasture and commercial agriculture are sizeable contributors to deforestation on a global scale. Agricultural fires typically used for land-clearing are increasingly spreading outside cultivated areas and into degraded rainforest regions.
Addressing deforestation issues - Addressing deforestation is a quite tougher job. Different needs and interests of various groups of people have to be taken into consideration while addressing the deforestation matter.
a. Rural farmers – Poor farmers are simply trying to put food on the table for their families. A better approach to addressing the needs of the rural poor may be improving and intensifying currently existing agricultural projects and promoting alternative cultivation techniques.
b. Industrial/commercial developers – At present, illegal logging and counterfeit labeling are major obstacles facing sustainable forest management for timber, but in time the development of higher yielding timber plantations will help alleviate pressures on natural forests. Increased raw material need of the emerging economies is again main reason of large scale deforestation, which need to be curtailed by promoting culture of recycling almost every product we use and by conservation.
c. Restoring and rehabilitating ecosystems – There is no use bemoaning past deforestation of large areas. Today the concern is how to best utilize lands already cleared so that, they support productive activities, now and for future generations. Without improving the well-being of people living in and around forests, we cannot expect rainforests to persist as fully functional systems and continue to cater to our needs. To lessen future forest loss, we must increase and sustain the productivity of farms, pastures, plantations, and scrub land in addition to restoring species and ecosystems to degraded habitats. By reducing wasteful land-use practices, consolidating gains on existing cleared lands, and improving already developed lands, we can diminish the need to clear additional forest.
d. Funding rainforest conservation efforts – Conservation efforts and sustainable development programs are not going to be cost-free. Even countries that already get considerable aid from foreign donors have trouble effectively making such initiatives work in the long term. Some of the following funding strategies may be considered:
(i) Ecotourism —Ecotourism can fund efforts both through park entrance fees and employing locals as guides and in the handicraft and service sectors etc.
(ii) Bio-prospecting fees —Rainforest countries can earn revenue by allowing scientists to develop products from the country’s native plant (e.g., with potential pharmaceutical applications etc.) and animal species. The royalties obtained from such commercial agreement should be set aside for conservation projects developed through local communities.
(iii) Carbon credits – For setting aside forest for the purpose of atmospheric carbon mitigation, developing countries can receive payments from industrialized countries looking to offset their carbon emissions.
(iv) Corporate sponsorship – Corporations have the money and a marketing-driven interest in taking a closer look at sponsorship issue.
e. Further steps to be taken once funding is in place – Further steps are to be taken in order to reduce deforestation activities, these are :
(i) Expand protected areas—As many areas should be protected as soon as possible. If protected areas can be developed in such a manner to generate income for local communities, an increasing number of parks should theoretically create more economic benefits for a greater share of the population.
(ii) Increase surveillance of and patrols in protected areas—This can be done at a reduced cost if local communities benefit from the success of the park. If locals have a vested interest, i.e. are compensated via entrance fees etc.; they will want to watch the park so that the source of their income is not diminished. Community surveillance is the most effective way to patrol a protected area, though it will probably be necessary to have park staff conduct patrols as well. Guides should be trained as well to keep watch for activities that are damaging to the ecosystem and report suspicious activities at park headquarters.
(iii) Build research facilities for training local scientists and guides.
(iv) Establish programs that promote sustainable use.
(v) Compensate displaced people.
(vi) Promote ecotourism.
(vii) Ensure economic success does not result in increased deforestation.
(viii) Encourage entrepreneurship – Encouraging entrepreneurship through such a micro-credit strategy could pay significant dividends for a country’s economy as a whole.
Conclusion – Simply banning the timber trade or establishing reserves will not be enough to salvage the world’s remaining tropical rainforests. In order for the forest to be preserved, the underlying social, economic, and political reasons for deforestation must be recognized and addressed
and here is a diagram.
here is another site...
[[http://rainforests.mongabay.com/0901.htm|]]http://rainforests.mongabay.com/0901.htm
here is the info. It answers "d" and a little of "e"
Rainforests around the world still continue to fall. Does it really make a difference? Why should anyone care if some plants, animals, mushrooms, and microorganisms perish? Rainforests are often hot and humid, difficult to reach, insect-ridden, and have elusive wildlife.
While in most areas environmental degradation has yet to reach a crisis level where entire systems are collapsing, it is important to examine some of the effects of existing environmental impoverishment and to forecast some of the potential repercussions of forest loss. Continuing loss of natural systems could make human activities increasingly vulnerable to ecological surprises in the future.
The most immediate impact of deforestation occurs at the local level with the loss of ecological services provided by tropical rainforests and related ecosystems. Such habitats afford humans valuable services such as erosion prevention, flood control, water treatment, fisheries protection, and pollination—functions that are particularly important to the world's poorest people, who rely on natural resources for their everyday survival. Forest loss also reduces the availability of renewable resources like timber, medicinal plants, nuts and fruit, and game.
Over the longer term, deforestation of tropical rainforests can have a broader impact, affecting global climate and biodiversity. These changes are more difficult to observe and forecast from local effects, since they take place over a longer time scale and can be difficult to measure
“It took more than 15 years for the "lungs of the world" myth to be corrected. Rainforests contribute little net oxygen additions to the atmosphere through photosynthesis.”
[[http://www.uneptie.org/pc/tourism/sust-tourism/env-conservation.htm</ref]]>
Ecosystem services
In addition to extractive human uses rain forests also have non-extractive uses that are frequently summarized as ecosystem services. Rain forests play an important role in maintaining biological diversity, modulating precipitation, infiltration and flooding, increasing scientific knowledge and in the spiritual well-being of humans. Such ecosystem services are of use to humans without the need for any modification or management of the forest yourself.Academic resources
- ''Agricultural and Forest Meteorology'' <ref name=afm>cite web
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| title = Agricultural and Forest Meteorology
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| url = http://www.sciencedirect.com/science/journal/01681923
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| accessdate = 20 January
| accessyear = 2009